Goldschmidt Abstracts 2010 – F

Goldschmidt Conference Abstracts 2010

A276

Trace and ultratrace elements in grapes: Possible applications for geographical traceability 1

1

2

F.A. FACCIA , C. VACCARO *, L. SANSONE , E. MARROCCHNO1 AND R. TASSINARI1 1

Dipartimento di Scienze della Terra, Universita’ di Ferrara, Via Saragat 1, 44100 Ferrara, Italy (*correspondence: [email protected] ) 2 CRA-Centro di ricerca per la viticoltura, Viale XXVIII Aprile 26, 31015 Conegliano, Italy In the last decades the demand of information and criteria, suitable for connecting products to their production regions, is becoming more urgent in order to protect the qualitative high level productions by forgery. Wine is one of the products that could benefit of a scientific system of analysis able to define its production area. Features of the association between wine and territory is not only related to pedological but also to geographical aspects. Currently several studies to define markers, such as isotopic ratios of O, C, and N, able to identify types of wine has been carried out, but they are not suitable to univocally define a specific type of wine in particular due to the high variability of some factors (temperature, age of vineyard, period of such us isotopic…). The aim of this work is to identify grape’s characteristic parameters in the Euganei Hills area (NE of Italy) considering that they have to be directly related to in soils and than in vines. Euganei Hills are an ideal test site because in this zone there is a high quantity of vines farms in soils with an high geochemical heterogeneity. Concentration of major (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K, P) and trace elements (Ba, Ce, Co, Cr, La, Nb, Ni, Pb, Rb, Sr, Th, V, Y, Zn, Zr, Cu, Ga, Nd, S, Sc) on 20 samples of soils (collected in a range of 30-40 cm of depth) and corresponding 20 samples of grapes has been analyzed by XRF. Moreover ICP-MS analysis has been carried out on wine grapes samples, with more attention on rare earth elements. In the investigated areas the grapes have shown typical concentration ratios of some trace and ultratrace elements suitable to identify the production areas.

Apollo 16 impact melt vs basalt: Textural and chemical analyses A.L. FAGAN* AND C.R. NEAL 156 Fitzpatrick Hall, Notre Dame, IN, 46556, USA (*correspondence: [email protected]) ([email protected]) This study builds upon previous work to distinguish between lunar impact melts and texturally similar pristine mare basalts. In the past, some lunar samples were initially incorrectly classified such as sample 14310, which was classified as a basalt [1-3], but later reclassified as an impact melt [4, 5]. Similarly, sample 14321, 1486 was identified as a basalt [6], but recently proven to be an olivine vitrophyre impact melt [7]. We use Crystal Size Distribution (CSD) textural analyses in conjunction with major and trace element mineral analyses to correctly categorize Apollo basalt and impact melt samples based on previous plagioclase work by [8]. Preliminary results suggest Apollo 16 basalts may have gentler plagioclase CSD slopes (Figure 1) than Apollo 14 impact melts and the three basalt groups [9] suggesting different crystallization conditions that could be correlated with the bulk composition (i.e. correlation between Al2O3 content and the CSD slope).

Figure 1: Plagioclase CSD of 60235, 2 (thick black) in contrast to Apollo 14 impact melts (thin black) and basalt groups (shades of grey). [1] Ridley et al. (1972) Proc. Lunar Sci. Conf. 3, 159–170. [2] Longhi et al. (1972) Proc. Lunar Sci. Conf. 3, 131–139. [3] Crawford M. & Hollister L. (1974) Proc. Lunar Sci. Conf. 5, 399–419. [4] Usselman & Lofgren (1976) Proc. Lunar Sci. Conf. 7, 1345–1363. [5] Lofgren (1977) Proc. Lunar Sci. Conf. 8, 2079–2095. [6] Neal et al. (1988) LPSC, XVIII, 139– 153. [7] Fagan et al. (2010) LPSC XLI, 2226. [8] Oshrin & Neal (2009) LPSC, XL, 1706. [9] Neal & Kramer (2006) Am. Min. 91, 1521–1535.

Goldschmidt Conference Abstracts 2010

The microstructure of Trinitite, the glassed sand from the first nuclear explosion A.J. FAHEY* AND D.E. NEWBURY

In July of 1945 the first test of technology for a nuclear weapon was conducted on the White Sands Proving Ground in New Mexico. The glassed sand that bears witness to the test is commonly referred to as Trinitite. Apart from several studies of the radioactivity in the material the only published work discussing the material from a mineralogical perspective was written in 1948 [1]. Most trinitite is a green glass that has a top Ô fusedÕ side that grades into the soil over 1-2 cm of depth. Trinitite is laden with vesicles that range in size from micrometers to nearly the thickness of the material. According to Ross [1], two types of glass were formed, one from the feldspars, clays and accessory minerals and the other from quartz. The silica glass mostly kept its original shape whereas the glass from the feldspar shows evidence of flow. We have found unusual features in a thin section of trinitite. These features show the effects of rapid melting and cooling.

2

Phase trasition from spinel lherzolite to garnet lherzolite in upper mantle of eastern China and its significance QICHENG FAN, JIANLI SUI AND BIN HAN

National Institute of Standards and Technology, Gaithersburg, MD 20899-8371, USA ([email protected]) (*correspondence: [email protected])

1

3

Institute of Geology, China Earthquake Administration, Beijin 100029 ([email protected]) It is well known that the upper mantle is stratified, either by petrological or geochemical layers. Mantle xenoliths, compared with garnet lherzolites from Sulu UHP belt, provide evidences of petrological (Sp to Gt transition) and geochemical variations of the upper mantle in eastern China. Spinel peridotites is wide spread in Cenozoic basalt in eastern China, while garnet bearing lherzolites only occur in several Cenozoic volcanic fields, e.g. Mingxi, Xilong, Hebi, Nushan, Hannuoba and Chaoerhe. P-T estimation by E-probe data reveal the petrological stratigraphy beneath the subcontinental lithospheric mantle of eastern China, as (1) Spinel lherzolites compose the uppermost mantle, (2) Sp/Gt lherzolites occur from 55-70 km, with temperatures of 10391182¡ C, and (3) Gt lherzolites occur more than 70km, with 115-1199¡ C. Rock type

Localities

T(
)

P(GPa)

D(km)

Sp/Gt

Mingxi

1058

2.05

66

Lherzolite

Figure 1: 1) Image (~5 µm across) of Ti-whiskers in melt, 2) Image (~250 µm across) of Zr-streak in melt, 3) Image (~100 µm across) of immiscible Fe spheres populating an elongated region near vesicles decorated with Fe spheres. Micro-structure shown in Fig. 1 is not completely unexpected but is somewhat confusing. Specifically, it is surprising that a Ô streakÕ of Zr-rich material (1-2) would form in the lower-temperature melt area but much of the quartz in the section appears un-melted. If the Zr-streak were once a zircon then we might expect it too, to be unmelted. Small whiskers of Ti appear in the melt near a vesicle (1-1) and spheres of Fe-rich material ranging in size from 300 nm down to <10 nm. Not shown are also inclusions of Y, Ba, and others. It may be that some of these unusual inclusions have their origin not as part of the original soil but as part of the weapon debris. If these unusual inclusions can be shown to have originated in the weapon then one may be able to discern clues that aid in its attribution. A key outcome of any forensic investigation of post-detonation material will be attribution. Further analysis must be performed to glean information. New data and other findings will be shown and discussed. [1] Ross (1948) Am. Mineral. 33(5,6), 360Ð 362.

A277

Xilong

1103

1.93

62

Nushan

1114

1.91

62

Hebi

1039

1.97

64

Hannuoba

1182

1.89

61

Gt

Chaoerhe

1164

2.36

76

Lherzolite

Xinchang

1115

2.47

79

Minqing 1199 2.43 77 Table 1: P-T estimation for garnet-bearing peridotites in Cenozoic basalts from eastern China T (!)Ñ by Wells (1977), P (GPa)Ñ by Nickel and Green (1985), D (km)=4.02+30.3P, Lallement et al. 1980. Chemical variation and stratigraphy of these samples provide essential evidence of mantle dynamic evolution in depth and/or through geologic time. In eastern China, garnet lherzolites from Sulu UHP belt have extremely Al-poor pyroxenes (0-0.2%wt Al2O3); garnet peridotites trapped in Paleozoic kimberlites from over 200 km depth are relatively Al depleted (Al2O3<2%wt); and the garnet lherzolites in Cenozoic basalts are Al-rich (Al2O3 4-5%wt). Supported by NSFC 40972047.

Goldschmidt Conference Abstracts 2010

A278

Geology characteristics of Fanshan alunite deposit in Lujiang-Zongyang continental volcanic basin in Eastern China 1

1

Y. FAN *, T.F. ZHOU , M.H. TANG AND F. YUAN 1

1

School of Resources and Environment Engineering, Hefei University of Technology, P.R. China (*correspondence: [email protected])

The Lu-Zong basin (Lujiang-Zongyang) is one of the most important Mesozoic continental volcanic basins in the Middle and Lower Reaches of Yangtze Metallogenic belt, eastern China. The basin comprises four shoshonitic volcanic rocks and corresponding intrusions. Fanshan deposit is one typical high-sulfidation alunite deposit in the Lu-Zong basin. The wall rock of the deposit includes Lower Cretaceous Zhuanqiao formation andesite, trachyte and volcanic tuff etc., and the main ore-control structure is monoclinal structure. The alteration zoning of the deposit is obvious and can be divided into silication zone, silication-pyritization-alunitization zone, kaolinization-alunitization zone and sericitizationchloritization zone from deep part to superficial part. The sections where alunitization are intensively developed are ore bodies. The deposit yields two type ores that are alunite-pyrite ore and alunite-kaolinite ores, separately. In Zhuanqiao formation, intense volcanic eruption produced large amount of the acidic ore-forming fluids which are enriched in H2S and SO42-. The ore-forming fluids reacted with andesitic and tuffaceous volcanic strata in rising process. After the alteration of feldspar minerals (including felsic vitric fragment and volcanic ash etc.), Al and K etc. ore-forming elements were separated out and combined with SO42- in oreforming fluids to form alunite, and iron-bearing minerals reacted with H2S minerals to form pyrite. Along with continuous moving up of gas and liquid, SO42- content in the in ore-forming fluids diminished unceasingly and formed alunite-kaolinite mineral assembly. While ore-forming fluid’s acidity declined, minerals such as sericite and chlorite had appeared to form alteration zoning of ore-forming fluid system. This research was supported by the National Natural Science Foundation of China (40803015, 4083042 and 40672062) and Major State Basic Research Development Program of China (2007CB411405).

Thermal evolution characteristics of Permian source rocks in Yongmei basin,, China HONGFENG FANG AND SUPING YAO Department of earth science, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210093, China ([email protected]) Many authors have reported that thermal evolution of organic matters in Volcanic –magmatic areas are generally high, which are normally controlled by magmatic process. The result of this study shows that samples from Yongmei basin have relatively high vitrinite reflectance (Ro)values (above3%). Ro values vary from 4-5% in the northwestern part of Yongmei, whereas 5-6% in the southeastern part. In a study of 4 coal wells from Yongmei basin, We observed that Ro values increase along with depth roughly, however, the correlation coefficient between Ro and depth is 0.31, indicating that burial is not the dominant factor on thermal evolution. Permian strata is characterized with illite crystallinity values from 2.5 to 4.2°("2#). A one- dimensional analysis of burial history and thermal evolution was carried out in 3 wells in Yongmei basin with the aid of onedimensional nonsteady numerical reconstructions. In the course of this thermal history, we believe hydrocarbons were generated as follows: Permian source rocks are in high maturity, entered threshold of oil generation during Early Triassic time, maximal paleogeotemperature up to 400 ! during Early Cretaceous time. There was no significant modification of hydrocarbon maturation history from Late Cretaceous to the Present. The conclusion shows organic maturation of Permian source rocks increases from northwest to southeast, so does magmatism scale. Permian strata lies in very low-grade metamorphic stage. The main factors responsible for heating the area are an elevated basal heat flow resulting from lithosphere thinning and widespread intrusive-thermal activity during Early Cretaceous time.

Goldschmidt Conference Abstracts 2010

A279

Fractionation of hydrogen isotopes in biosynthesis of fatty acids by piezophilic bacterium Moritella japonica DSK1

Zircon oxygen and Hf isotopic constraints on 150 m.y. of subduction magmatism, South Patagonian Batholith, South America

J. FANG1*, L. ZHANG2, C. LI3, D.H. BARTLETT4 5 AND C. KATO

C.M. FANNING1, F. HERVÉ2, R.J. PANKHURST3, M. CALDERÓN2, G.M. YAXLEY1 AND P. HOLDEN1

1

Department of Natural Sciences, Hawaii Pacific University, 45-045 Kamehameha Hwy., Kaneohe, HI 96744, USA 2 State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, China University of Geosciences, Wuhan, Hubei 430074, China 3 Division of Geological and Planetary Sciences, MC100-23, California Institute of Technology, Pasadena, CA 91125, USA 4 Scripps Institute of Oceanography, University of California, San Diego, Mail Code: 0202, 9500 Gilman Drive, La Jolla, CA 92093, USA 5 Research Program for Marine Biology and Ecology, Extremobiosphere Research Center, JAMSTEC, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan We examined stable hydrogen isotope fractionation in biosynthesis of fatty acids of a piezophilic bacterium Moritella japonica strain DSK1. DSK1 was grown to stationary phase at 30 MPa in media prepared using sterile-filtered natural seawater supplied with glucose with the sole carbon source. Saturated, monounsaturated, cyclopropane and polyunsaturated fatty acids were identified. All fatty acids were depleted in D relative to growth water and glucose, but in different extent. Saturated fatty acids exhibited less fractionation than monounsaturated fatty acids which had less fractionation than polyunsaturated fatty acids. There was significant difference in !D between different groups of fatty acids. Polyunsaturated fatty acids were more depleted in D, ranging from -127 to -215‰ relative to saturated FA, and from -150 to -173‰ relative to monounsaturated fatty acids. This pattern of !D discrepancy between different groups of fatty acids is similar to that of carbon isotopes we observed in the same bacterium before [1], further suggesting that the interpretation of carbon and hydrogen isotope signatures of marine lipids must be based on principles derived from piezophilic bacteria. [1] Fang et al. (2006) Geochim. Cosmochim. Acta 70, 1753– 1760.

1

Research School of Earth Sciences, Australian National University, ACT 0200, Australia ([email protected]) 2 Departamento de Geología, Universidad de Chile, Casilla 13518, Correo 21, Santiago, Chile ([email protected]) 3 British Geological Survey, Keyworth, Nottingham NG12 5GG, United Kingdom ([email protected])

Magmatic and inherited zircon in the South Patagonian Batholith (SPB) provides a rare opportunity to examine a 150 my record of subduction-related magma genesis in the Cordilleran margin of south-western South America. It also enables us to track changes in plate configurations and movements. U-Pb dating has shown that the oldest intrusions are late Jurassic (150-157 Ma), in part coeval with the waning stage of more widespread, mainly silicic, Jurassic volcanism in southern South America. Thereafter, magmatic events were episodic through to the Neogene. Whole-rock Sm-Nd data highlighted a general progression through time from more crust-derived magma sources to those that are more juvenile. SHRIMP oxygen isotope and LA-MC-ICP-MS Lu-Hf data provide a far greater insight into the evolution of the SPB. !18O values are high in the late Jurassic (ranging to +8) indicating crustal magma sources. !18O values decline rapidly during the Late Jurassic and early Cretaceous to indicate mantle-derived sources (from +5.0 to +5.6) and even lower to values typical of hydrothermally-altered sources. With the passage of time, crustal sources were relatively quickly consumed by magma generation. Involvement of crustal melting gave way to primitive, and hydrothermally altered sources for the generation of the middle Cretaceous and younger plutons. The "Hf data support this model; Late Jurassic magmas have negative values (ranging to -9), rising to positive values by early Cretaceous and remaining so through to the Neogene. Significantly the Hf data indicate that whilst sources were primitive from the middle Cretaceous, they had already had a significant crustal residence time. The sympathetic behaviour of zircon !18O and "Hf with time can be linked to larger scale changes in plate configurations and movements, such as the closure of the Rocas Verdes Basin in the early Cretaceous.

A280

Goldschmidt Conference Abstracts 2010

Groundwater quality analysis in the vicinity of brick kilns along the highway road of Rawalpindi and Islamabad

Going beyond the mystery mineral: Extending the use of powder X-ray diffraction in an introductory mineralogy course

A. FAROOQI1 AND M. RAMZAN2*

DORI J. FARTHING

1

Fatima Jinnah Women University, Rawalpindi, Pakistan ([email protected]) 2 Fatima Jinnah Women University, Rawalpindi, Pakistan (*correspondence: [email protected])

The research was conducted to determine the effect of 3540 brick kilns in an area of 4-5sq. m on ground water quality along the highway road of Rawalpindi and Islamabad. Fifty water samples (50) ranging in depth of 50-400m were collected from 7 different residential colonies in the vicinity and surrounding area of brick kilns. Results of water analysis showed alkaline pH ranging from 7.7-8.9 with the mean value of 8.3. Electrical conductivity (EC) ranges from 546-4750 uS/cm with mean value of 1465 uS/cm. Total Dissolved Solids (TDS) ranges from 410-3563 mg/l with the mean value of 1098 mg/L and turbidity ranges from 2.4-196 NTU with mean value of 8.96 NTU. Alkalinity (as HCO3-) ranges from 317-1293 mg/l with the mean value of 521 mg/L. Total hardness ranges from 312748 mg/l with the mean value of 505 mg/L. Ca++ ranges from 168-652mg/l with the mean value of 383 mg/L while, Mg++ ranges from 10-236mg/l with the mean value of 122.2mg/l.Nitrates ranges from 2.5-30.7mg/l with the mean value of 17.4mg/l, Chloride ranges from 12.8-706mg/l with the mean value of 146.3mg/l and Lead ranges from 0.030.86mg/l with the mean value of 0.47mg/l. Piper plot shows that water of brick kiln areas is of Ca-HCO3 type. The relationship between Cl- vs. SO42-, F- and NO3- was studied. They all showed positive correlations with Chloride. Positive correlation was also obtained between pH and F-.Calcium showed negative correlation with F- and HCO3-. Results of the analysis showed that samples of areas in the proximate neighbourhood of brick kilns were found more contaminated as compared to the samples of distant areas. Low quality fuel such as tyre, sulphur enriched coal etc used during the burning process, are the culprits of contamination. Bio fuels should be used as an alternative to avoid contamination of great underground water reservoir. During the survey of brick kiln areas, health effects were also noticed. People dwelling in the areas are suffering from various respiratory and dental diseases.

SUNY Geneseo, Department of Geological Sciences, 1 College Circle, Geneseo, NY 14454, (*correspondence: [email protected]) Students at SUNY Geneseo are participating in a new project aimed to improve their sense of connection between their mineralogy course and their personal lives. ‘Project Relevancy’ provides students with hands-on experience with analytical instrumentation, experimental design, and data interpretation. This project ultimately seeks to make it very clear to students that we live in a world of crystalline materials that are often mineral-based. ‘Project Relevancy’ builds upon the experience of students identifying unknown minerals with XRD and challenges them to investigate the mineral content (or crystalline character) of a household material of their choosing. The students must prepare it (being conscientious of creating a flat surface for analysis), interpret the results, and share their findings with their colleagues. Since the project’s inception, Geneseo students have analyzed materials such as evaporated mouthwash, lip balm, chewing gum, and index cards. Assessment of ‘Project Relevancy’ indicates that students have an increased appreciation for the relevance of mineralogical topics. Students indicated in post-project comments that they also better understood the benefits (and also the shortcomings) associated with XRD analysis. Students involved in ‘Project Relevancy’ also demonstrated an increased sense of confidence and self-efficacy when carrying out search and match procedures to identify their materials. In particular, they were more willing to throw out computerprovided matches compared with students attempting to identify a mystery mineral.

Goldschmidt Conference Abstracts 2010

Geochemistry of fly ash-brine co-disposal systems: Solubility controls on trace elements O.O. FATOBA1*, W.M. GITARI1, L.F. PETRIK1 2 AND E.I. IWUOHA

Selective chemical extraction of heavy metals and arsenic in soils contaminated by mining activity (Northern Portugal): Biogeochemical implications

1

Environmental and Nano Science Research Group, Chemistry Department, University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa (*correspondence: [email protected]) 2 SensorLab, Chemistry Department, University of the Western Cape, Private Bag X17, 7537, South Africa

Fly ash is a waste material generated from coal combustion in power stations. Fly ash, which contains major and trace elements such as Ca, Mg, Na, K, SO4, Cl, As, Se, Zn, Cd, Pb, Cu and Mo among others, are produced in significant quantities in South African power utilities. Apart from the generation of fly ash, a hyper-saline wastewater known as brine is also generated in significant quantity during coal combustion processes. Brine contains major elements such as Na, Cl, Ca, SO4, K, Mg in large quantities, and trace elements such as Fe, Mn, Cr, V, Ti, P, Si, and Al (1). There is need to safely dispose these waste materials due to the possible release of contaminants to the surrounding soils and groundwater. Due to the ability of fly ash to effectively adsorb species in wastewaters (2), the co-disposal of fly ash and brine is expected to result in precipitation of salts, which may result in effluents with reduced TDS. It is expedient to understand the geochemistry of the fly ash-brine co-disposal systems. The study aims at understanding the solubility controlling the release or removal of trace species in the fly ash ash-brine systems. Fly ash and brine were reacted in a batch reaction test at different reaction times varying from 5 minutes to 24 hours. The filtrates from the batch reaction tests were analyzed for trace elements using ICP-MS. The results of the tests revealed the removal of some species such as As, Cu, Pb and Zn from the brine solution. PHREEQC geochemical modeling predicted that the saturation indices (SI) for some mineral phases such as Cupricferrite (CuFe2O4) and Ba3 (AsO4)2, were oversaturated while Pb (OH)2 and Zn (OH)2 were almost at equilibrium. [1] Turek (2004) Desalination 162, 355–359. [2] Erol et al. (2005) Energy Conversion & Management 46, 1319–1331.

A281

PAULO FAVAS1,3, JOÃO PRATAS2,3 AND ELISA GOMES13 1

Dep. of Geology, UTAD, Ap.1013, 5000-801 Vila Real, Portugal ([email protected]) 2 Dep. of Earth Sciences, University of Coimbra, Largo Marquês de Pombal, 3001-401 Coimbra, Portugal 3 Geosciences Center, University of Coimbra A chemical sequential extraction of heavy metals (Fe, Mn, Cu, Zn, Pb, Cd, Sn, W, Bi, Ni, Cr, Mo, Co) and As in tailings and soils samples around a five W/Sn mines (Northern Portugal) was realized using a 7-steps fractionation procedure [1]: (1) water-soluble; (2) exchangeable; (3) bound to Fe oxyhydroxides (easily reducible); (4) bound to Fe oxides (moderately reducible); (5) bound to organic matter and secondary Cu-sulfides; (6) bound to primary sulfides; (7) residual. The extracted element contents were measured by ICP-MS. Samples were also analysed for pH, electrical conductivity and organic matter. The results allowed us to notice that: 1) The pH was the main factor for controlling the geochemical distribution of the studied elements. The tailing and soil samples were very acid, with an average pH of approximately 4, 37. Some metal cations (Mn, Cd, Cu, Zn, Pb, Co, Cr, Ni) behave in a similar way, revealed important enrichments in the most bioavailable fractions (water-soluble and exchangeable fractions). In contrast, oxyanions as Mo and As show low mobility through adsorption to Fe (III) oxyhydroxides dissolved in the two reducible fractions. These results reflect the pH dependent adsorption on the clay minerals, Fe and Mn oxyhydroxides and the co-precipitation with these secondary minerals; 2) Residual fraction was the most important fraction for Sn, Mn, Cr and Zn. These results suggest that in these soils these elements are in a detrital, non available form; 3) Scavenging of mobilized elements (mainly Fe, Mn, Cu, Zn, Cd, Pb, W, Bi, Mo, Cr, Ni, Co and As) in secondary mineral phases and sulfides could be considered a temporary mechanism of metal retention. These metal fractions are susceptible of being set free depending on some changes of environmental conditions. [1] Dold & Fontboté (2001) ‘Element cycling & secondary mineralogy in porphyry copper tailings as a function of climate, primary mineralogy, & mineral processing.’ J. Geochem. Explor. 74, 3–55.

A282

Goldschmidt Conference Abstracts 2010

O and H diffusion in uraninite: Implications for fluid-uraninite interactions and nuclear forensics M. FAYEK1*, L.M. ANOVITZ2, D.R. COLE2 2 AND D.A. BOSTICK 1

Dept. Geological Sciences, University of Manitoba, Winnipeg, MB R3T2N2, Canada (*correspondence: [email protected]) 2 Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA Diffusion coefficients for O and H were determined from a series of uraninite-H2O experiments between 50 and 700 °C. Under hydrous conditions there are two mechanisms of diffusion: (1) an initial extremely fast-path diffusion mechanism that overprinted the O isotopic composition of the entire crystals regardless of temperature and (2) a slower volume diffusive mechanism dominated by defect clusters that displace or eject nearest neighbour O atoms to form two interstitial sites, two partial vacancies, and by vacancy migration. Using the volume diffusion coefficients in the temperature range 300-600 °C, diffusion coefficients for O can be represented by D = 2e-5 exp (-29489 cal/RT) cm2/sec and for temperatures between 100-300°C the diffusion coefficients can be represented by D = 2e-10 exp (-14934 cal./RT) cm2/sec, where the activation energies for uraninite are 29.5 kcal/mole and 14.9 kcal/mol, respectively. Hydrogen diffusion in uraninite is controlled by similar mechanisms as O. Using the volume diffusion coefficients in the temperature range 50-700 °C, diffusion coefficients for H can be represented by D = 9e-6 exp (-37411 cal/RT) cm2/sec for temperatures between 450 and 700 °C and D = 1e-14 exp (-8250 cal/RT) cm2/sec for temperatures between 50 and 400 °C, where the activation energies for uraninite are 37.4 kcal/mole and 8.3 kcal/mol, respectively. Exceptionally low !18O values of natural uraninites (i.e. 32‰ to -19.5‰) from unconformity-type uranium deposits in Saskatchewan, in conjunction with theoretical and experimental uraninite-water fractionation factors, suggest that primary uranium mineralization is not in O isotopic equilibrium with coeval clay and silicate minerals. The low !18O values have been attributed to O isotopic exchange with recent meteoric water (!18O = -20‰) at temperatures <50°C. Our data show that the anomalously low O isotopic composition of the uraninite can be a result of meteoric wateruraninite interaction under reducing conditions. The rather fast O and H diffusion coefficients for uraninite, especially at low temperatures, suggest that O and H diffusion studies can be used to track the route of fissile material from origin to location.

Can Fe isotopes be used to fingerprint Precambrian BIF? C.M. FEDO1*, M.M. HAGE1, R. SCHOENBERG2 3 AND M.J. WHITEHOUSE 1

Dept. Earth & Planetary Sciences, University of Tennessee, Knoxville, TN 37996 USA (*correspondence: [email protected]) 2 Center of Geobiology & Dept. of Earth Science, University of Bergen, Bergen, Norway 3 Laboratory for Isotope Geology, Swedish Museum of Natural History, Stockholm, Sweden The Fe isotope composition of BIF, with !56Fe ratios ranging from -2 to +1.5 ‰, stands in marked contrast to the overwhelming majority of iron reservoirs on Earth [1]. Consequently, Fe isotopes might have potential to identify BIF protoliths in strongly altered and metamorphosed rocks (e.g. [2]). Here we report data from two groups of samples: (1) genuine BIF representing ages from 1.9 Ga to ~3.8 Ga, and (2) non-sedimentary samples. All of the genuine BIF samples studied so far have bulk-rock Fe isotope compositions that are consistent with a BIF ‘fingerprint’ (-0.239 ‰ < !56Fe < +1.046 ‰). However, the Fe isotope signatures of the non-chemical sedimentary samples suggest a more complicated story. A banded jasper+magnetite rock from the Abitibi Greenstone Belt has !56Fe = +1.25 ‰, and thus lies within the expected confines for a chemical sediment, as does a relatively pure metasomatic carbonate sample from the Isua Greenstone Belt (IGB; !56Fe = -0.350 ‰). Three other samples that have a mineral assemblage inconsistent with a sedimentary origin, have fractionated negative !56Fe values that range from -0.206 to -0.188 ‰, which is similar to a BIF sample from the IGB. Although the expected range of Fe isotope compositions occurs in our BIF samples, non-sedimentary samples share those values, and so it seems impossible to fingerprint BIF with Fe isotopes. [1] Johnson & Beard (2006) GSA Today 16, 4–10. [2] Dauphas et al. (2004) Science 306, 2077–2080.

Goldschmidt Conference Abstracts 2010

Geochemical investigation of crude oil samples from West Siberia Megabasin YU.N. FEDOROV1*, A.V. MASLOV2, YU.L. RONKIN2, V.G. KUTCHEROV3 AND V.P ALEKSEEV4 1

KogalymNIPIntft, Tyumen, Russia (*correspondence: [email protected]) 2 Institute of Geology and Geochemistry SB RAS, Ekaterinburg, Russia 3 Royal Institute of Technology, Stockholm, Sweden 4 Ural State Mine University, Ekaterinburg, Russia Results of the geochemical investigation of 30 samples of crude oil from different West Siberian oil fields are presented. To determine a distribution of rare, rare-earth and platinoid group of elements in the samples ICP-MS analyses with high resolution mass-spectrometer and preliminary acid distraction was used. The experimental results obtained show that terrigen fine-grained rocks composing reservoir layers of Tyumen’ and Abalak suites are characterized by Rh-Ir specialization. While the samples of crude oil extracted from these rocks have PdRu specialization. Study of samples of bitumen located in source rocks of the Bazhenov suite show that the samples investigated have Pd-Rh specialization. The results obtained together with theoretical and previous experimental results [1, 2] give us the possibility to suggest that accumulation and/or transformation of oil deposits in West Siberian Mega basin could take place at essential influence of deep fluids. [1] Letnikov (2005) Proc. Russ. Acad. Sci. 402, 205. [2] Kutcherov et al. (2002) Proc. Russ. Acad. Sci. 387, 789!!

A283

The paleomagnetism and age of the Modipe Gabbro, South Africa JOSHUA M. FEINBERG1, S.W. DENYSZYN2, P.R. RENNE2 2 AND G.R. SCOTT 1

Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota, 55455-0219, USA 2 Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California, 94709, USA

The Precambrian Modipe Gabbro outcrops as isolated hills along the South Africa-Botswana border and was the focus of an influential paleomagnetic study by Evans and McElhinny (1966) that is frequently used to anchor the apparent polar wander path of the Kaapvaal craton. The characteristic remnant magnetization (ChRM) of the intrusion was reported to be held by elongate, single-domain inclusions of magnetite exsolved in pyroxene and characterized by high median destructive fields (~40-60 mT). Until recently, the emplacement age of the Modipe Gabbro was poorly constrained and the only available ages were those of McElhinny (1966): a Rb-Sr date of 2630 ± 470 Ma and a series of K-Ar dates measured from a pyroxene mineral separate ranging from 2600 to 3000 Ma. We report U-Pb analysis of ten single grains of baddeleyite (ZrO2) yielded a 207Pb/206Pb age of 2784.0 ± 1.5 (2!) Ma with an MSWD of 1.7. This is by far the most precise age determination yet for the Modipe Gabbro and is interpreted to reflect the time of emplacement. However, light microscopy reveals an absence of magnetite inclusions of the type described by Evans and McElhinny (1966), and extensive alteration of pyroxene (to actinolite) and plagioclase (to epidote and sericite). Despite the absence of inclusions and the ubiquitous mineralogical alteration, the mean ChRM calculated after alternating field demagnetization (Dec. 189°, Inc. 89°, a95 7.4°) is indistinguishable from that of earlier workers (Dec. 155°, Inc. 85°, a95 5.4°), raising the possibility that the ChRM reported by Evans and McElhinny (1966) is not held solely by pyroxene-hosted inclusions, or conversely, that it is a secondary magnetization unrelated to the age of emplacement. This age corresponds with that of the nearby Gaberones granite suite (2783-2785 Ma) (Moore et al. 1993), and places the Kaapvaal craton at the same latitude as the Pilbara craton based on ca. 2770 Ma flood basalts in Australia (Strik et al. 2003; Wingate 1998), supporting the Vaalbara hypothesis in placing the two continents together at ca. 2.8 Ga.

Goldschmidt Conference Abstracts 2010

A284

Does fluid transport in the mantle wedge determine radiogenic isotope ratios in arc magmas?

The role of intermediates during metal carbonation of forsterite in wet supercritical CO2

MAUREEN FEINEMAN

A.R. FELMY1*, J.H. KWAK1, J.Z. HU1, K.M. ROSSO1, C. WANG1, D.W. HOYT1, E.S. ILTON1, J.R. RUSTAD2 3 AND D.A. DIXON

Dept of Geosciences, Pennsylvania State University, University Park, PA, 16802, USA, [email protected] 1

Radiogenic isotope ratios are commonly used to distinguish the relative inputs of subducted oceanic crust, subducted sediments, and mantle wedge material to the generation of arc magmas. Most mixing models assume that fluids (whether they be aqueous, silicate melts, or supercritical) faithfully retain the isotopic ratios of their slab sources during transit to the melt source region in the mantle wedge. This assumption drives much of the physical modeling of fluid transport in the mantle wedge. Relaxation of this assumption, however, allows us to explain some otherwise puzzling features of arc magmas, and to test the robustness of isotopic tracers under a variety of circumstances. For example, modeled slab-derived fluid compositions based on measured arc magma compositions indicate that some Sr isotope compositions in fluids are considerably less radiogenic than would be expected for altered oceanic crust, or a mixture of crust and sediment. In such cases we must conclude that a) the Sr contribution from the slab has been over-estimated, b) the composition of the subducted crust is not what we believe it to be, or c) the composition of the slab-derived fluid has been altered prior to arrival at the melting source region. Simple numerical models are used to show that fluids released from the slab can exchange Sr with the mantle wedge if reactive transport is allowed, causing the Sr isotope ratios in the fluids to be subtly decreased toward mantle values prior to reaching the magma source region. The extent of exchange depends on the cumulative rock/fluid ratio experienced during transport. At the same time, the Pb isotope ratios of the initial fluids will be retained. Thus Pb is a robust tracer of slab (both crust and sediment) inputs to arc magmas, while Sr isotope ratios in fluids may not necessarily reflect those in the subducted slab.

Pacific Northwest National Laboratory, Richland, WA 99352 (*correspondence: [email protected]) 2 The University of California-Davis, Davis, CA 95616 ([email protected]) 3 The University of Alabama, Tuscaloosa, AL 35487 ([email protected])

The capture and storage of carbon dioxide and other greenhouse gases in deep geologic formations represents one of the most promising options for mitigating the impacts of greenhouse gases on global warming. As a result there has been a focus on evaluating mineral-fluid interaction for subsurface CO2 storage in aqueous solutions in contact with supercritical CO2 (scCO2). However, at the interface with the caprock over the long term, interactions with neat to watersaturated non-aqueous fluids are of equal if not more importance given recent observations that wet scCO2 is immediately reactive with steel, cement, and certain mineral assemblages. In such a scenario, it is of vital importance to understand the mechanistic role of small quantities of water dissolved into the scCO2 fluid in mineral carbonation reactions. Here we present results on the metal carbonation of forsterite (Mg2SiO4) as a function of water content in scCO2 solutions conducted at 80°C and 80 atm pressure. NMR and TEM analysis of the reaction products showed that at high water contents where an aqueous solution was present forsterite was converted into magnesite and an amorphous SiO2-like reaction product. As the amount of added water became limiting, intermediate reaction products could be identified until at zero added water no reaction products were observed. Intermediate reaction products identified both by NMR, XRD, and molecular simulation is dypingite [Mg5 (CO3)4 (OH)2•5H2O] and a complex mixture of partially hydrated/hydroxylated Q1 and Q2 silica, the latter of which implies consumption of water via hydrolysis of Mg-O-Si linkages. If insufficient water is available, the reaction does not proceed far enough to form magnesite and SiO2 reaction products. Water in excess of this limit yields the crystalline reaction products, a process that in turn is expected to liberate water. Hence, for a given fluid/forsterite ratio there is a water concentration threshold above which water serves in a catalytic role for the carbonation process.

Goldschmidt Conference Abstracts 2010

Biogeochemically induced mineral transformaitons controlling the fate of arsenic SCOTT FENDORF*, YOKO MASUE, BEN KOCAR AND SAMANTHA YING Earth System Science, Stanford University, Stanford, CA 94305 (*correspondence: [email protected], [email protected], [email protected], [email protected]) Dissolved concentrations of arsenic within pore-waters of soils and sediments are controlled by a composite of biogeochemical reactions. Generally, arsenic binds strongly to soil/sediment solids under aerated conditions; under anaerobic condition, aqueous concentrations generally increase, a phenomenon attributed to reduction of iron or arsenic. We show that reduction of arsenate to arsenite nearly universally increases the lability of arsenic, thus stimulating its migration within surface and subsurface environments. Iron reduction, conversely, can either increase or decrease the retention and lability of arsenic depending on the initial iron phase, the surface composition, the rate of reaction and resulting Fe (II) concentration, and the extent of reduction. Whether arsenic is released to solution or incorporated into secondary transformation products during microbial reduction of Fe (III) is firstly dependent on the host phase. Ferrihydrite is particularly prone to Fe (II) induced transformation to thermodynamically more stable phases that include goethite and magnetite. Upon formation of these secondary phases, particularly magnetite, arsenic (III) (which is also produced by biological reduction) can be incorporated into the surface structure, and thus decrease (rather than increase) aqueous concentrations of arsenic. However, the secondary hosts may be short-lived and themselves undergo reductive dissolution (without reprecipitation), ultimately leading to an increase in dissolved arsenic. Moreover, both surface moeities (e.g. phosphate) as well and structural dopants (e.g. Al) modify the transformation pathway of ferrihydrite and may therefore limit formation of secondary phases that can host arsenic. Here we illustrate that structural incorporation of Al within ferrihydrite, along with the surface coverage of arsenate and phosphate, diminish ferrihydrite transformation to magnetite or goethite and thus promote arsenic release to solution. Within the complex structure of natural soils and sediments, biogeochemical conditions (and associated reactions) will vary over small (sub-micron) scales, thus leading to micron-scale variation in reactions involving arsenic. Using constructed and natural aggregates, we illustrate variations in biogeochemical conditions and the resulting fate of arsenic.

A285

U/Th dating of cold-seep carbonates: Timing and duration of fluid seepage D. FENG1,2*, H. CHENG3, H.H. ROBERTS2, J. PECKMANN4, G. BOHRMANN4 AND D.F. CHEN1 1

CAS Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, CAS, Guangzhou 510640, China (*correspondence: [email protected]) 2 Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803, USA 3 Department of Geology and Geophysics, University of Minnesota, MN 55455, USA 4 MARUM, University of Bremen, Post Box 330 440, D-28334 Bremen, Germany Authigenic carbonates from hydrocarbon seeps are unique archives of past seepage and environmental parameters. Here, we report U/Th ages of such carbonates from Gulf of Mexico, Congo Fan, and Black Sea. Our aim was to investigate the timing and duration of fluid seepage on continental margins. In order to acquire U/Th ages of cold-seep carbonates, it is important to choose proper sample to test and evaluate the amout of initial 230Th accurately. The obtained U/Th ages suggest that environmental conditions must have been favorable for enhanced methane-rich fluid seepage during the time interval of 10 to 1.7 ka for Atwater Valley 340, 11.7 to 8.6 ka, and 53 to 45 ka for Alaminos Canyon 645 of the Gulf of Mexico, 45 to 3 ka for Congo Fan, and 1.7 to 0.5 ka for Black Sea sites. Overall, our results indicate that hydrocarbon seepage was discontinuous at the investigated sites. The short life span of seepage at a particular locality is probably controlled by the exhaustion of the hydrocarbon sources, and/or clogging of the plumbing system due to extensive carbonate formation. It seems that vigorous seepage initiated at the end of the last deglaciation in the Gulf of Mexico, reflecting a time of sedimentary loading and associated salt diapirism that activated the fault conduits to the seafloor. Seepage in the Congo Fan and Black Sea may have been a function of the stability of the gas hydrate reservoirs, which probably were affected by environmental change in the course of Late Quaternary climate change, including variations in bottomwater temperatures. This study was supported by 973 Program (2009CB219506) and the NSFC (40906031 and 40725011).

A286

Goldschmidt Conference Abstracts 2010

Variations in the distribution and radiocarbon age of lignin phenols exported by large river systems

A preliminary study on the mechanism of methylmercury accumulation in rice at abandoned mercury mines in Guizhou, China

XIAOJUAN FENG1*, DANIEL B. MONTLUCON2 3 AND TIMOTHY I. EGLINTON

XINBIN FENG1, BO MENG1,2, GUANGLE QIU1, HUA ZHANG1,2, PING LI1 AND LIHAI SHANG1

1

Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA (*correspondence: [email protected]) 2 Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA ([email protected]) 3 Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA ([email protected])

As a major component of vascular plant woody tissues and soil organic matter, lignin is widely distributed in coastal marine sediments through fluvial transport from the terrestrial environment. However, the transformation of lignin within river drainage basins and the timescales over which it is delivered to the oceans is not well understood. Here we describe analytical details and preliminary results on the distribution and isotopic composition of lignin-derived phenols in sedimentary particles from several major river systems that span a range of latitudes, extending from Arctic (Mackenzie and Lena), temperate (Columbia, Fraser, and Yangtze), to tropical regions (Congo and GangesBrahmaputra). These drainage basins are each characterized by large fluxes of terrestrial organic carbon and also encompass a variety of climatic and hydrological conditions. Investigating the provenance and transport of lignin in these areas allows for the assessment of environmental, geomorphic and other factors controlling the dispersal and burial of terrestrial organic carbon in the marine environment. Molecular markers of lignin are isolated by copper oxide oxidation, followed by high pressure liquid chromatography (HPLC), and further purified for compound-specific 14C isotopic analysis. The efficiency of the lignin seperation method and the accuracy of radiocarbon measurement was tested on authentic phenol standards as well as on lignin phenol extracts from wood samples of pre-determined radiocarbon age. The radiocarbon contents of lignin phenols extracted from the sediments are compared with those of leaf wax lipids in order to provide insights on the cycling of different components of vascular plant organic matter within fluvial systems. Overall, our approach enables development of a comprehensive perspective on the transformations and fate of terrestrial organic carbon during riverine transport to the marine environment.

1

State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China

The main objective of this study is to investigate the mechanism of methylmercury (MeHg) accumulation in rice by determining the MeHg levels and distributions in rice plants from a mercury mined area (Wanshan) and a control site (Huaxi). The experiment groups were designed as follows 1) Group 1, a rice paddy field in Huaxi, with low Hg in soil and low Hg deposition flux; 2) Group 2, an experiment box in Huaxi with soil from Wanshan, with high Hg in soil and low Hg deposition flux; 3) Group 3, a rice paddy field in Wanshan, with high Hg in soil and high Hg deposition flux; 4) Group 4, an experiment box in Wanshan with soil from Huaxi, with low Hg in soil and high Hg deposition flux. During the rice growing season (from June to September 2007), we collected samples once every two weeks, including precipitation, soil samples from the rice seeding roots, surface water samples from the rice paddy field and experiment box, pore water in soil, rice plant including roots, stalks, leaves, and seeds, and DOC, ORP and pH in soil pore water. THg and MeHg were measured in all samples according to US EPA Method 1631 and Method 1630. The results revealed that the main active transformation of inorganic Hg to MeHg takes place in rice paddy soil, and the newly deposited Hg is much easier to be transformed to MeHg and accumulated in rice than the ‘old’ Hg in soil. An interesting outcome of this study is the observation that seeds have the highest ability to accumulate MeHg than other tissues of rice plants (roots, stalks, leaves etc.).

Goldschmidt Conference Abstracts 2010

Imaging interfacial topography and reactivity with X-rays

Developing radiocarbon within California mollusk shells as a proxy of upwelling intensity

P. FENTER1*, S.S. LEE1, C. PARK2, J. CATALANO3, Z. ZHANG4 AND N.C. STURCHIO5

J.E. FERGUSON1*, L. MEYER2, K.R. JOHNSON1, G.M. SANTOS1, K. ACAYLAR1 AND A. TRIPATI3

1

Chemical Sciences and Engineering, Argonne National Laboratory, Argonne IL 60439. (*correspondence: [email protected]) 2 HP-CAT (Geophysical Laboratory, Carnegie Institution of Washington), Argonne, IL 3 Department of Earth and Planetary Sciences, Washington University at St. Louis, St. Louis, MO 4 Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 5 Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago IL A fundamental understanding of aqueous-mineral interface reactivity is essential for developing robust predictive models that describe elemental transport in the near-surface environment. X-ray reflection interface microscopy (XRIM), a powerful new tool for interfacial studies, has been demonstrated recently at the Advanced Photon Source. XRIM is analogous to a simple optical microsope, but is unique in that it uses the weak interfacereflected X-ray beam to create an image. It therefore incorporates all of the sensitivities of X-ray reflectivity (XR), including sensitivity to interfacial structure and composition, along with the ability to spatially resolve heterogeneous systems and processes. This presentation will review recent and anticipated applications of XRIM as a probe of geochemical processes. Initial studies performed on the orthoclase (001) surface (ex-situ observations of reacted surfaces in air) have demonstrated: the ability to see elementary surface topography with ~100 nm spatial resolution [1]; progress in understanding the basis for the contrast in these XRIM images [2]; and the first application of XRIM to investigate interfacial reactivity [3]. Ongoing success in the use of XRIM as an in situ probe of the mineralwater interface will also be presented along with the specific challenges of in situ studies, including an intrinsically reduced signal strength and avoiding radiation damage. Future improvements in the XRIM instrument and its use as an in situ real-time probe of interfacial processes will be discussed. [1] Fenter et al. (2006) Nature Physics 2(10), 700–704. [2] Fenter et al. (2008) Journal of Synchrotron Radiation 15, 558–571. [3] Fenter et al. (2010) Geochimica et Cosmochimica Acta, in review.

A287

1

Department of Earth System Science, University of California, Irvine, Croul Hall, Irvine, CA 92697 (*correspondence: [email protected]) 2 Massachusetts Institute of Technology, Cambridge, MA 02139 ([email protected]) 3 Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1565 Our understanding of the complex interactions between the California Current strength, upwelling intensity and El Niño Southern Oscillation (ENSO) is currently limited by the short duration of instrumental records and a lack of suitable seasonal-resolution marine archives. Marine mollusk shells provide a seasonal-resolution archive with significant potential. Living mussels (Mytilus californianus) were collected from Newport Beach, California. Sequential samples were micromilled from the outer calcite layer of shell cross-sections and analyzed for stable isotopes, trace elements and radiocarbon. By comparing the geochemical profiles produced from the shells with instrumental records and ocean geochemical measurements, including seawater dissolved inorganic carbon (DIC) radiocarbon, made at a nearby site over several years it is possible to identify empirical relationships between shell geochemistry, upwelling and oceanic variables. We also present results from Mytilus californianus shells collected from Mexico to Oregon following the strong El Niño event of 1997-1998. This event caused a collapse of upwelling and provides an ideal test of the fidelity of these empirical relationships along the west coast of North America at a time of dramatic change within the California Current system.

A288

Goldschmidt Conference Abstracts 2010

Grapes and wines on basic anorogenic volcanic rock terrains in South Lessini (Italy): Geochemical fingerprint and heavy metals assimilation G. FERIOLI1, P. BARTOLOMEI2, M. ESPOSITO1, E. MARROCCHNO3, L. SANSONE4*, R. TASSINARI3 3 AND C. VACCARO 1

U-SERIES, Via Ferrarese, 131, Bologna ([email protected]) ENEA, via dei Colli, 16, 40136 Bologna 3 Centro di Microscopia Elettronica, UniversitaÕ di Ferrara 4 CRA-Centro di Ricerca per la Viticoltura, Viale XXVIII Aprile, 26 31015 Conegliano (TV) (*correspondence: [email protected]) 2

In the 2009 in some experimental sites in Veneto (Vicenza and Treviso Provinces) has been collected 36 samples of soils in order to define, through XRF analysis, the content (wt%) of major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K, P) and the concentration (ppm) of trace elements (Ba, Ce, Co, Cr, La, Nb, Ni, Pb, Rb, Sr, Th, V, Y, Zn, Zr, Cu, Ga, Nd, S, Sc). Moreover on 4 samples of grape juices, 4 samples of wines (cultivars Fiano, Verdicchio, NeroD! Avola e Refosco p. r.) and 2 samples of grapes (NeroD! Avola e Refosco p. r.) has been determined, using ICP-MS technique, the concentration of the most important trace elements (Li, Be, B, Na, Al, K, Rb, Ca, Sr, Ba, Mg, Mn, Fe, V, Cr, Co, Ni, Cu, Zn, Ga, As, Se, Mo, Ag, Cd, Sb, Te, Hg, Tl, Pb, Bi, U). These analysis has been useful to define quality of wines and grapes, typical ratios of every soils considered and to identify the geochemical fingerprint in an area where climatic differences are slightly important to influence the assimilation dynamics. In this work has been defined the relationship between soil matrix and wines through the comparison of the heavy metals concentration. Also for the purposes of food security, for both provinces concerned, were performed in gamma spectrometry analysis to determine the levels of natural radionuclides (238U, 232 Th and 40K) and 137Cs.

Organic carbon and microbial remnants in Mazon Creek fossils A. FERNANDES*, A. HILLS, C. TSUJITA AND G. SOUTHAM Dept. of Earth Sciences, The University of Western Ontario, London, ON, Canada, N6A 5B7 (*correspondence: [email protected]) Mazon Creek Area fossils represent a KonservatLagerst$tten formed in Northeastern Illinois during the Middle Pennsylvanian. Concretions found in the Francis Creek Shale Member of the Carbondale formation were deposited in a deltaic-estuarine environment. Samples collected from a spoilheap of Ô Peabody Coal Company Pit 11Õ were analyzed using light microscopy, SEM, SEM-EDX, µXRD, and ToF-SIMS. The fossil concretions consist of mainly Essex (marine) with some Braidwood (terrestrial and freshwater) flora and fauna. One concretion was determined to contain the scyphomedusan Essexella asherae. Examination of a polished section using scanning electron microscopy revealed a well-developed pyrite film and halo surrounding this organism, containing discontinuous crystal aggregates of non-framboidal pyrite, suggesting bacterially mediated pyrite aggregation at organic fronts. Detrital quartz clasts, clay grains, and micrometer-sized Ô coccoidÕ bodies were found cemented throughout the siderite matrix, suggesting suspension within bacterially-derived extracellular polymeric substance during early concretion development (Fig. 1). ToF-SIMS analysis of clot-like organic remains between siderite crystallites revealed CN, CNO, and C4H to C14H hydrocarbon groups. Reflected light micrographs of two worm-like concretions have revealed black spots throughout the siderite matrix that may contain organics. SEM, SEM-EDX and ToF-SIMS analysis of the worm-like concretions and other representative organisms will help determine the role of microorganisms in the formation and preservation of Mazon Creek Fossils.

Figure 1. Scanning electron micrograph of Essexella polished section showing bacterial texture (scalebar = 10 µm)

Goldschmidt Conference Abstracts 2010

A289

Water organization in Na-saponite: An experimental validation of numerical data

Contrasting sources of magmatic epidote-bearing monzodiorites and tonalites, NE Brazil

E. FERRAGE1*, B.A. SAKHAROV2, L.J. MICHOT3, B. LANSON4, A. DELVILLE5 AND G.J. CUELLO6

V.P. FERREIRA1*, A.N. SIAL1, M.M. PIMENTEL2, R. ARMSTRONG3, M.J. SPICUZZA4, I.P. GUIMARÃES1 1 AND A.F. DA SILVA FILHO

1

HYDRASA UMR6269-CNRS, 86022 Poitiers, France (*correspondence: [email protected]) 2 Geological Institute, RAS, 119017 Moscow, Russia 3 LEM UMR6531-CNRS, 54501 Vandoeuvre, France 4 LGCA UMR5025-CNRS, 38041 Grenoble, France 5 CRMD UMR6619-CNRS, 45071 Orléans, France 6 Institut Laue Langevin, 38042 Grenoble, France The crystal-structure and stepwise hydration behaviour of smectite as a function of relative humidity (RH) have been extensively studied by X-ray diffraction (XRD). Although powerful, XRD accounts poorly for the actual statistical positional disorder of interlayer water. Computational simulations provide relevant information by supplying detailed molecular pictures of the system. Still, relatively few studies have confronted simulation results with experimental data and existing comparisons do not allow assessing the validity of the semi-empirical atomic interaction parameters used in theoretical simulations. Hydration behaviour of two synthetic Na-saponites with different layer charges (0.4 and 0.7/O10 (OH)2) was studied by XRD from 92% RH down to ~ 0% RH. Calculated XRD patterns were then fitted to experimental profiles to determine for each sample the RH conditions to obtain almost homogeneous mono-hydrated and bi-hydrated state. Additional neutron diffraction (ND) patterns on both H2O and D2O saturated specimens were used to increase the contrast of sensitivity of the modelling approach towards water. Layer thickness derived from XRD was used to constrain a simulation box for Grand Canonical Monte-Carlo simulations (GCMC-µ, V, T). The obtained density profiles of interlayer species were then introduced for calculation of XRD and ND patterns whereas water content was compared to that determined from gravimetric water sorption measurements. The proposed collation procedure between GCMC and XRD/ND methods provides a quantitative critical assessment of the numerous potentials and different models used for microscopic simulations of interlayer water.

1

Department of Geology, Federal University of Pernambuco, Recife, PE, 50.740-530, Brazil (*correspondence: [email protected]) 2 Institute of Geosciences, University of Brasília, Brasília, DF, Brazil 3 Research School of Earth Sciences, the Australian National University, Canberra, Australia 4 Department of Geosciences, University of Wisconsin, Madison, USA The 618 Ma Curral de Cima tonalite and the 577 Ma Lourenço monzodiorite in the eastern Alto Pajeú terrane, northeastern Brazil, are examples of magmatic epidote-bearing plutons. Both plutons carry ferrohornblende, biotite, titanite and epidote. Amphibole-rich clots (ARC) are only present in the Curral de Cima tonalite; co-magmatic dioritic enclaves are present in the Lourenço pluton. Major, trace and isotope chemistry suggest that the major rocks of the two plutons probably followed similar differentiation trends but formed from protoliths derived from age and compositionally different source rocks. Whole-rock and mineral chemistries of the two plutons have similar yet very distinct evolution trends in variation diagrams, with almost no overlap. The mineral phases and the predominantly metaluminous nature of the Curral de Cima tonalite, the presence of ARC, and obvious juvenile component (average "Nd = -3.55; average 87Sr/86Sr = 0.7083; TDM = 1.36 Ga), all point to an I-type source for these rocks. These data together with high calculated !18O (whole rock) (10.0‰) for the tonalite and high !18O value for an ARC (9.3‰) are compatible with the hypothesis that ARC represent fragments of an hydrothermally altered metabasaltic source rock. On the other hand, average !18O (whole rock) for the Lourenço monzodiorite is 7.8‰, average 87Sr/86Sr = 0.7083, "Nd (0.57Ga) values are strongly negative (average -14.6), and TDM = 1.92 Ga. These data are compatible with long residence time and probably reflect a mixture of igneous sources (Neoproterozoic juvenile magma) and ancient radiogenic Mesoproterozoic crust as source rock.

A290

Goldschmidt Conference Abstracts 2010

Putting fluid salinity and solid solution into transport models

Isotope tracing of CO2 seepage: Results from controlled release experiment in Bozeman, Montana

J.M. FERRY1*, N.W. WINSLOW1 AND M. GOTTSCHALK2

J. FESSENDEN1*, K. GUILLKERSON2, L. DOBECK2, H. RAUCH3 AND L. SPANGLER2

1

Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA (*correspondence: [email protected]) 2 GeoForschungsZentrum Potsdam, Division 3, Geodynamics and Geomaterials, Telegrafenberg, 14773 Potsdam, Germany ([email protected]) We developed methods that explicitly consider salinity and solid solution in modeling infiltration-driven carbonation and decarbonation reactions produced by 1-D fluid flow along T- and P- gradients relevant to metamorphism. The effect of (A) salinity was evaluated by parameterizing XCO2 of H2OCO2-NaCl fluid in equilibrium with reactants and products as a function of XNaCl of the input fluid (X°NaCl, in the range 0.00.3 or 0-58 wt% NaCl) and distance along the flow path. The effect of (B) solid solution was evaluated by parameterizing XCO2 of H2O-CO2 fluid in equilibrium with reactants and products as a function of reaction progress (#), XCO2 of the input fluid (X°CO2), and distance along the flow path. The distribution of mineral products along the flow path was then computed as function of X°NaCl, X°CO2, and time-integrated input fluid flux (TI2F2) both analytically and with a finitedifference method. Principal results are: (A) For mineral-fluid equilibrium at the reaction site, the TI2F2 required to displace a mineral reaction front a given distance along the flow path always increases with increasing X°NaCl, by a factor of up to 1.4-7.9 for X°NaCl up to 0.3, depending on the reaction and P-T conditions [1]. Immiscible fluid phase separation and differential loss of the liquid (L) or vapor (V) phase from the reaction site always increases the TI2F2 required to advance the reaction front a given distance compared to equilibration of minerals and fluid with no loss of L or V. (B) When reactions involve solid solutions, the slowest moving value of # typically corresponds to initial reaction. For input of fluid with disequilibrium X°CO2 into a single layer, a sharp reaction front develops, and TI2F2 can be computed exactly. For layerparallel flow where multiple layers equilibrate with the same flowing fluid, layer-by-layer varations in # with # < #maximum can develop depending on the mode, initial mineral compositions, and thickness of each layer. For input of fluid with equilibrium X°CO2 and reaction driven by flow along Pand T-gradients, TI2F2 can be computed to within ~10% simply using a single #-averaged value of XCO2 at the reaction site. [1] Ferry & Gottschalk (2009) CMP 158, 619–636.

1

Los Alamos National Laboratory, EES-14, Los Alamos NM 87545 (*correspondence: [email protected]) 2 Montana State University, Chemistry and Biochemistry, Bozeman MT ([email protected], [email protected]) 3 University of West Virginia, Geology and Geography, Morgantown VA ([email protected]) The geological storage of carbon dioxide (CO2) captured from the emissions of combustion of fossil fuels is a promising option to mitigate the increase in atmospheric greenhouse gases. Within the past 10 years, efforts in understanding the storage capacity, chemical and physical alteration, and the leak potential of CO2 impact to various reservoir types have been researched both at the laboratory and field. State-of-the-art monitoring equipment and models in the areas of geophysics, geochemistry, atmospheric chemistry, and remote sensing are being employed within this research area. Specifically, over the past 4 years, a controlled field experiment has taken place in Bozeman, Montana where pure CO2 has been released at known rates and depths to quantify the detection limits of various monitoring techniques. A 87 m buried pipe located 2 m below the soil surface is in place and over the past 4 years of experimentation, a range in CO2 injection rate and time (0.1 ton/day to 0.3 ton/day for 10-30 days depending upon year) has been monitored by a variety of monitoring equipment. The monitoring tool highlighted in this paper, is the use of stable isotope detection of CO2 seepage into atmospheric, vegetation, and groundwater reservoirs. Results show a distinct isotopic impact to the local groundwater (at 1.2 m depth), surface CO2 (chamber and canopy) within 24 hours after injection, and vegetation (7 m from CO2 source). Quantification of seepage CO2 versus natural CO2 in these reservoirs is discussed.

Goldschmidt Conference Abstracts 2010

Strontium isotopes in Chilean rivers: The flux of unradiogenic continental Sr to seawater KATHERINA FIEGE2*, CHRISTIAN A. MILLER1,3, LAURA F. ROBINSON1, RICARDO FIGUEROA4 1 AND BERNHARD PEUCKER-EHRENBRINK 1

Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA ([email protected], [email protected]) 2 Institute of Geosciences, University of Heidelberg, 69120 Heidelberg, Germany (*correspondence: [email protected]) 3 MIT/WHOI Joint Program in Oceanography, USA 4 Aquatic Systems Research Unit, Environmental Science Center EULA-Chile, University of Concepcion, PO Box 160-C, Concepcion, Chile ([email protected]) Water samples from Chilean rivers were analyzed for Sr/86Sr and Sr concentrations and the average 87Sr/86Sr and continental Sr flux to the southeastern Pacific Ocean. This drainage region had not been studied before, but is similar in its geologic makeup to young, volcanically active arcs and ocean islands that may contribute disproportionately to the seawater Sr budget. Data indicate that the average yield of unradiogenic Sr (~517 moles Sr km-2 yr-1, 87Sr/86Sr ~0.7057) from western South America (1, 220, 853 km2) [1] into the southeastern Pacific Ocean is ~2-4 times higher than that from Iceland [2] [3] and the Deccan traps [4], but lower than fluxes of unradiogenic Sr from ocean islands in the Lesser Antilles and Réunion [5]. Active convergent continental margins release about as much unradiogenic Sr to seawater as a 0-1 Myr old mid-ocean ridge segment of equivalent length. The flux of unradiogenic Sr from active continental margins has likely varied over geologic time scales in response to changes in the surface exposure of volcanic arcs, changes in climate, ocean currents and geographic latitude due to plate tectonics, as well as topographic changes that can affect local rainfall, runoff and erosion. It is therefore likely that active continental margins have contributed to the observed temporal variations in seawater 87Sr/86Sr 87

[1] Fiege et al. (2009) Chem. Geol. 268, 337–343. [2] Baumgartner & Reichel (1975) Amsterdam: Elsevier, 179 pp. [3] Gannoun et al. (2006) EPSL 243, 732–748. [4] Dessert et al. (2001) EPSL 188, 459–474. [5] Rad et al. (2007) EPSL 262, 109–124.

A291

Effect of chlorine on near-liquidus phase equilibria of basalts JUSTIN FILIBERTO, 1 RAJDEEP DASGUPTA1 2 AND ALLAN H. TREIMAN 1

Rice University, Department of Earth Science, 6100 Main Street, MS-126, Houston, TX 77005 ([email protected], [email protected]) 2 Lunar and Planetary Insitute, 3600 Bay Area Blvd., Houston, TX 77058 ([email protected]) Volatiles have enormous effects on the formation and crystallization history of basaltic magmas. Previous work on basalt genesis has focused mainly on the effects H2O and CO2 [e.g. 1, 2]. Yet, basaltic magmas can contain up to ~1 wt% Cl [e.g. 3] and little is known about the effects of Cl on basalt genesis [4]. Therefore, we have experimentally investigated the effects of Cl on phase equilibria of basalt. We have conducted piston cylinder experiments at 1.1 GPa on an Fe-rich model basalt composition with 0-1 wt% chlorine added. Nominally Cl-free experiments yield olivine (Fo77) on the liquidus at 1425°C while the experiments with 0.4 wt% and 1 wt% Cl both yield opx as the liquidus phase (En79Wo2 at 1400°C for both Cl concentrations). This shows that Cl extends the orthopyroxene stability field to lower pressure, thereby shifting the olivine-orthopyroxene-melt multiple saturation point to much lower temperatures and shallower depths. The orthopyroxenes of the Cl-added experiments are more magnesian and less calcic than those from the Cl-free experiments (En79Wo2 vs. En76Wo4). We infer that the opx liquidus field is extended because Cl complexes with Ca and Fe (and perhaps Mg) in the melt, and thus increases the melt’s silica activity. Experiments with other chlorine concentrations at wider pressure range are in progress, and should lead to a robust parameterization of the effects of chlorine on basaltic liquidi. Because the presence of chlorine increases the pyroxene stability field with respect to olivine, the compositions of basaltic melts produced by partial melting of mantle lithologies may be different. This effect is similar to that of CO2 [2] and may be similarly important in the genesis of alkalic basalts, which are commonly enriched in chlorine [5]. This effect may also help explain the presence of alkali basalts on Mars which is argued to be a chlorine-rich planet [6]. [1] Médard & Grove (2008) Contrib. to Min. & Pet. 155, 417– 432. [2] Dasgupta et al. (2007) J. Pet. 48, 2093–2124. [3] Johnston D.A. (1980) Science. 209, 491–493. [4] Filiberto & Treiman (2009) Chem Geo. 263, 60–68. [5] Dixon et al. (1997) J. Pet. 38, 911–939. [6] Filiberto & Treiman (2009) Geology 37, 1087–1090.

A292

Goldschmidt Conference Abstracts 2010

New approaches to identifying and reducing persistent lead exposure pathways to urban populations

Factors controlling the stabilization of above and belowground plant biopolymers in soil

GABRIEL M. FILIPPELLI1, DEBORAH MORRISON-IBRAHIM1, GILBERT LIU2 2 AND SARAH WIEHE

TIMOTHY FILLEY1, COLLEEN IVERSEN2 3 AND JULIE JASTROW

1

Dept. of Earth Sciences, Indiana Univ. – Purdue Univ. Indianapolis (IUPUI), IN, USA ([email protected]) 2 Dept. of Pediatrics and Indiana Children’s Health Services Research, IUPUI

A new paradigm has emerged to explain the continued exposure of urban children to lead (Pb). Although acute Pb poisoning is caused by exposure to discrete Pb sources like Pb-based paints, large proportions of urban children exhibit chronic lower-level Pb poisoning, resulting in well-known and permanent neuro-cognitive defects. A source for chronic Pb poisoning is exposure to Pb-contaminated urban soils, which have retained a century of Pb deposited from leaded gasoline, Pb-based paints, and industries. Given a soil-based exposure pathway, the mitigation strategy to reduce Pb is straightforward but daunting--separate the urban population from the high-Pb surface horizon of soils. Wholesale removal is not a viable economic option. Instead, we are developing a surgical approach to targeting and remediating communitylevel ‘hotspots’ by analyzing the coupled spatial relationship of soil Pb contamination and human exposure. Our earlier analyses of soil Pb:Pb poisoning in Indianapolis revealed a key community in Indianapolis with high soil Pb and high rates of blood Pb poisoning. We have collected and analyzed over 250 soil samples from this community, have targeted homes in these areas for interior dust Pb sampling, and have identified several discrete areas with soil Pb levels significantly above urban background level. We also received full-spectrum blood Pb level data, to the address scale, for ~16, 000 children from 0-5 year olds. With the spatial analysis of blood Pb levels of children, we can develop risk models to analyze the costs of soil remediation and to add address ‘triggers’ for clinicians to order Pb tests.

1

Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN USA 2 Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA 3 Biosciences Division, Argonne National Laboratory, Argonne, IL USA The relative contribution and stabilization of above ground litter and roots is an important consideration when determining the response of ecosystems to drivers that influence soil carbon accrual and loss. We investigated soil carbon dynamics of a sweet gum plantation exposed to free air CO2 enrichment (FACE) for ten years. We applied a combined biomarker, stable isotope, and soil physical fractionation approach to assess the proportion of root and leaf derived material within particulate (microaggregated and nonmicroaggegated) and clay/silt-associated carbon. Additionally, to assess decay dynamics of roots grown under high and low CO2 conditions, we also conducted a root decay study. Factors such as plant productivity and chemistry, edaphic properties, and invertebrate activity, all have a control on the proportion, depth, and chemistry of soil carbon stabilized in this system. Indications of root vs. leaf input to soil physical fractions and earthworm casts were derived from differences in the chemical and isotope composition of alkaline CuO-derived lignin and substituted fatty acids (SFA) from cutin and suberin. Decay pathways alter the composition of specific released monomers from root and leaf but even after extensive decay root and leaf SFA remain distinguishable. Over time we found that non-microaggregated particulate carbon shifted to greater suberin-like SFA. Endogeic species were proportionately more responsible for fine root cycling while some epigeic species were responsible for microaggregation of foliar cutin. As earthworm species abundance and activity are not is steady state in many forests, the important role of these invertebrates should be considered when assessing the changing soil state.

Goldschmidt Conference Abstracts 2010

Magnesium in palaeoenvironmental carbonates ADRIAN A. FINCH1*, NICOLA ALLISON1, LAURA FOSTER1,2, LINDSAY WILSON3 4 AND ED HATHORNE 1

School of Geography & Geosciences, University of St Andrews, KY16 9AL, UK 2 Department of Earth Sciences, University of Bristol, Queen's Road, Bristol BS8 1RJ, UK 3 Institute for Geology, University of Tromsø Dramsveien 201 N-9037 Tromsø, Norway 4 DIFM-GEOMAR, Leibniz Institute of Marine Sciences, University of Kiel, D-24148 Kiel, Germany We compare the Mg K-edge X-ray Absorption Near Edge Structure (Mg K-XANES) of a range of standards and biominerals to determine Mg structural state. Our samples include planktonic foraminifera and tufa (calcite), and corals, speleothem, bivalves and sclerosponges (aragonite). Biogenic calcites have XANES similar to inorganic calcite, with the exception of Globigerina bulloides, which has the XANES of aragonite. No biogenic aragonite studied gives XANES consistent with aragonite as a host. The XANES most closely match the Mg-bearing organic standard. The XANES of organics is structureless because Mg is surrounded by elements with poor electron scattering and little long-range order. Similar XANES would also be produced by nanoparticulate material in which long-range electron resonances are absent. This is the structure of amorphous calcium carbonate (ACC), which has short-range order and particle sizes of ~50 nm. Although the exact nature of the host in unclear, we conclude that Mg in aragonitic biominerals is not hosted by macroscopic aragonite.

A293

Selenium retention by iron sulfides N. FINCK1,3*, K. DARDENNE1 AND D. BOSBACH2,3 1

Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), Campus Nord, P.O. Box 3640, D-76021 Karlsruhe (Germany) (*correspondence: [email protected]) ([email protected]) 2 Institute for Energy Research 6 (IEF-6), Forschungszentrum Jülich, D- 52425 Jülich (Germany) ([email protected]) 3 Helmholtz Virtual Institute “Advanced Solid-Aqueous RadioGeochemistry” (Germany)

Ubiquitous in nature, iron sulfides (FeS and FeS2) are believed to control the in situ redox potential (reducing conditions) of most rock formations envisaged for the dispoal of HLW. Pyrite (FeS2), the most stable authigenic iron (II) sulfide phase in the environment, can be formed via several pathways, with FeS often being the initial precipitate [1]. Both substrates are scavenger of trace elements from solution in anoxic environments. 79Se (T1/2 > 105 yrs) is one of the elements of concern for the safe storage of High Level nuclear Wastes (HLW). The chemistry of selenium resembles that of sulfur, and occurs at low oxidation states under reducing conditons. The retention of selenide by adsorption on and by coprecipitation with iron sulfides were investigated in this work. Amorphous mackinawite (FeSam) was precipitated in the presence of selenide [2]. Information on the Se oxidation state (XANES) and crystal-chemical environment (EXAFS) were obtained from X-ray absorption spectroscopy (XAS). Upon coprecipitation with FeSam, XANES data pointed to the presence of a reduced Se species associated with the bulk solid. Analysis of the EXAFS data suggested the presence of successive Fe and S shells, typical of mackinawite. The results were consistent with Se incorporation in the bulk solid. In contrast, XANES data suggested a partial oxidation of Se (-II) upon contact with FeSam in suspension. The Se near-range environment by surface reaction also differed from the coprecipitation experiment (EXAFS). Specifically, lower number of neighboring atoms and a distant Se shell (d (Se-Se) ~ 3.6 Å) were detected. The results pointed to an oxidative retention involved in the surface reaction. Preliminary tests were also conducted to prepare Se-doped pyrite from the doped precusor phase (FeSam) [2]. First XANES data suggested a partial oxidation of Se, a behavior identical to S when oxidizing FeIIS-IIam to FeS2. [1] Butler & Rickard (2000) GCA 64, 2665–2672. [2] Lingane & Niedrach (1948) JACS 70, 4115–4120.

Goldschmidt Conference Abstracts 2010

A294

The impacts of coal on human health ROBERT B. FINKELMAN

Are rock dissolution rates predictable from lab experiments? CORNELIUS FISCHER1,2, ROLF S. ARVIDSON1 1 AND ANDREAS LUTTGE

Department of Geosciences, University of Texas at Dallas, Richardson, TX 75080 1

Although all forms of energy use can impact human health none can match coal for the long history of use, breath and severity of the impacts or for the number of misconceptions. Particulates and noxious gases released from coal combustion have caused health problems for centuries but recent technological advances have significantly reduced the health threat from coal use. Nevertheless, combustion of coals containing high concentrations of trace elements such as As, F, Se, and Hg still, under certain circumstances, adversely impact health. Balkan endemic nephropathy, an irreversible kidney disease, is related to leaching of toxic organic compounds by groundwater passing through lignite deposits. When the water is ingested, these compounds contribute to the health problem. Although there is limited information on uncontrolled coal fires, it is probable that their emissions cause health problems for both the miners and villagers. Recent studies have shown that the most widely recognized disease of coal miners, ‘black lung disease,’ may be initiated by inhalation of finely divided pyrite liberated by coal mining. Concerns over the health impact of radioactivity from coal and coal combustion byproducts are unjustified. The levels of radioactive material in virtually all coals and most coal combustion byproducts are in the same range as most surficial rocks and soils. Direct health problems caused by coal and coal use are generally local but potentially severe. Once identified, practical solutions are available. For people living in areas where high quality coal is burned in modern boilers using the best available pollution control technology and sensible coal combustion byproduct disposal practices, the health threat is minimal. Human health problems caused by coal combustion-induced climate change may be a topic for future research.

2

Rice University, Houston TX, 77005, USA Georg-August-Universität, D-37077 Göttingen, Germany ([email protected], [email protected], [email protected])

Inhibition processes such as formation of secondary minerals or microbial activity will modify mineral reaction rates in nature. Here we investigate occurrence, amount, and scale of surface reactivity anisotropy and consequences on mineral weathering kinetics. Calcite dissolution rates [1] show variations of about 3 orders of magnitudes on crystal surface sections of 5 %m x 5 %m compared to only minor variation for sections of 100 µm x 100 µm. We conclude that the frequency distribution of crystal lattice imperfections may result in an anisotropy of surface reactivity and topography up to the micron scale. This has important implications for the evolution of porosity and permeability in rocks and, moreover, the predictability of dissolution kinetics of minerals in the environment. A comparison of the discussed calcite dissolution rate range to the dissolution rate of fine-grained, very lowpermeable, calcitic microcrystalline limestone shows significant differences even after normalization of the submicron surface area via roughness parameters [2]. This underlines the importance of an anisotropic surface reactivity for the propagation of fluid-accessibility to high-reactivity domains in mineral aggregates and rocks. [1] Morse et al. (2007) Chem. Rev. 2007, 342–381. [2] Fischer & Luttge (2007) Amer. J. Sci. 307, 955–973.

Goldschmidt Conference Abstracts 2010

Geochemical effects of CO2 on brinesaturated reservoir sandstones

Time-resolved XRD of the siderophore-promoted dissolution of birnessite

S. FISCHER1,2*, A. LIEBSCHER1, M. WANDREY1, G. FRANZ2 AND CO2SINK GROUP

T.B. FISCHER1*, P.J. HEANEY1, S.L. BRANTLEY1, J.E. POST2 AND M. TIEN3

1

GFZ German Research Centre for Geosciences, Centre for CO2 Storage, Telegrafenberg, D-14473 Potsdam, Germany (*correspondence: [email protected]) 2 Technical University of Berlin, Faculty VI, Section Mineralogy, Ackerstraße 76, D-13355 Berlin, Germany

Long-Term CO2 Exposure Experiments In order to investigate geochemical changes during geological CO2 storage in a saline aquifer, core samples from the target horizon (Upper Triassic Stuttgart Formation) at Ketzin, Germany, have been saturated with synthetic reservoir brine and exposed to CO2 at simulated in situ P-T-conditions of 5.5 MPa and 40°C. After 15 months, a first set of samples was removed from the high quality steel autoclaves and compared with their untreated twin samples. Supplementary core samples have been taken out after 21 and 24 months, respectively. Further core fragments will remain in the pressure vessels for longer-term experiments.

Discussion of Results The samples are mainly fine-grained, well to moderatelywell sorted and weakly consolidated sandstones. Quartz and plagioclase are the major components, while K-feldspar, white & dark mica, hematite, chlorite and illite are present in minor and varying amounts. Cements occur as isolated, poikilitic patches and are composed of analcime, anhydrite and subordinate dolomite. The plagioclase composition determined by EMP analysis indicates preferred dissolution of the Ca-component and a trend toward Na-rich compositions up to pure albite (albitization) during the experiments. Additionally, XRD data suggest anhydrite dissolution in the course of CO2 exposure. SEM micrographs show corrosion textures, such as dissolution holes, etched pits and lamellae, on mineral surfaces of e.g. plagioclase and K-feldspar. Unaltered, idiomorphic albite grains of some CO2-treated samples suggest albite precipitation. The chemical evolution of the brine displays increased Ca2+ concentrations [1] in line with the preferred dissolution of anorthitic plagioclase and anhydrite. [1] Wandrey et al. (2010) ‘Monitoring petrophysical, mineralogical, geochemical & microbiological effects of CO2 exposure–Results of long-term experiments under in situ condition.’ GHGT 10, submitted.

A295

1

Department of Geosciences, Pennsylvania State Univ., University Park, PA 16802, USA (*correspondence: [email protected]) 2 Department of Mineral Sciences, Smithsonian Institution, Washington, DC 20013-7012, USA 3 Department of Biochemistry and Molecular Biology, Pennsylvania State Univ., University Park, PA 16802, USA

We used synchrotron time-resolved X-ray diffraction (TRXRD) to track the complete dissolution of birnessite, a layered Mn (III, IV) oxide, by a siderophore. Siderophores are biogenic molecules that can significantly influence the cycling of transition metals in soils. Researchers have demonstrated that siderophores break down Mn oxide minerals through the formation of siderophore-Mn complexes in solution (e.g. [1]). Previously, we explored the reductive dissolution of birnessite by membranes of Shewanella oneidensis [2]. In the present study, we wanted to compare the crystallographic effects of membrane-mediated and siderophore-promoted dissolution. Using a flow-through reaction cell, we monitored birnessite dissolution via desferrioxamine B (DFOB) (0.01 and 0.001 M). X-ray diffraction experiments were conducted at the Advanced Photon Source beamline 13 BM-C, and diffraction patterns were collected every 70 s. In all experiments, the loss of birnessite increased linearly with time until its complete disappearance. Rietveld analysis revealed no significant change in unit-cell parameters until ~70 wt% of the birnessite had dissolved. Beyond this point, the birnessite c-axis decreased by a small (~0.01 Å) amount. This contraction was an order of magnitude smaller than that associated with membrane-mediated dissolution. Based on our Scherrer particle size analysis, we postulate that the slight decrease in c during siderophore dissolution represents nanoscale strain rather than structural distortion due to multiple redox reactions, as occurred during membranemediated dissolution. Our results reveal for the first time that in situ crystallographic analyses of dissolving solids can distinguish among different mechanistic pathways of structural collapse. [1] Duckworth & Sposito (2007) Chem. Geol. 242, 497–508. [2] Fischer et al. (2008) Am. Min. 93, 1929–1932.

A296

Goldschmidt Conference Abstracts 2010

Silicon isotope constraints on the formation of the Moon

Structure-catalytic activity relationship of biogenic Pd nanoparticles

CAROLINE FITOUSSI1, BERNARD BOURDON1, KAVEH PAHLEVAN2 AND RAINER WIELER1

J.P. FITTS1*, D. CHIDAMBARAM2, T. HENNEBEL3, S. TAGHAVI1, N. BOON3, W. VERSTRAETE3 1 AND D. VAN DER LELIE

1

Institute of Geochemistry and Petrology, ETH Zurich, Switzerland ([email protected]) 2 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 USA

The formation of the Moon by a giant impact could have significantly affected the isotope composition of moderately volatile elements such as silicon. The analysis of Si isotopes in lunar rocks, compared with terrestrial rocks and chondrites, can thus potentially provide insights into the Moon-forming event. The Si isotope compositions of several high- and low-Ti mare basalts were measured with the MC-ICPMS NuPlasma 1700. The Si isotope composition of the silicate Earth and Moon is identical within error while it is distinct from that of the chondrites [1, 2]. At the time of the impact, the !30Si of the Earth’s mantle is well represented by the measured modern value, given that most of the Earth’s core must have formed before the Moonforming giant impact [3]. Therefore, at that time, the Earth’s mantle already had its heavier-than-chondritic Si isotope composition. In order to account for the similarity of other isotope systems between Earth and Moon silicate phases [4-6], a model involving isotope equilibration through turbulent fluid exchange between the terrestrial magma ocean and the surrounding melt-vapor proto-lunar disk following the giant impact has been suggested [7]. Since the isotopic homogeneity of the Earth-Moon system includes both volatile and refractory elements, turbulent exchange may have involved both the silicate vapor and the suspended liquid droplets, isotopically homogenizing all elements irrespective of their volatility. In such a scenario, the terrestrial value of the Si isotope composition of lunar samples can be explained through inheritance from Earth’s mantle. The vaporization of silicates in the proto-lunar disk could also have produced Si isotope compositions distinct from the terrestrial value by equilibrium liquid-vapor Si isotope fractionation. Depending on the amount of phase separation that occurs, this scenario can result in a lunar Si isotope composition that is lighter than the terrestrial value [8]. The precision of the Si measurements (&maximum $30SiMoon-Earth) constrains the scenario of liquid rainout in the post giant-impact atmosphere of the Earth. [1] Fitoussi et al. (2009) EPSL 287, 77. [2] Georg et al. (2007) Nature 447, 1102. [3] Rudge et al. submitted. [4] Wiechert et al. (2001) Science 294, 345. [5] Touboul et al. (2007) Nature 450, 1206. [6] Trinquier et al. (2008) GCA 72, 5146. [7] Pahlevan & Stevenson (2007) EPSL 262, 438. [8] Pahlevan et al. submitted.

1

Brookhaven National Lab, Upton, NY 11973, USA (*correspondence: [email protected]) 2 University of Nevada Reno, Reno, NV 89557-0388, USA 3 Ghent University, B-9000 Gent, Belgium We have identified a highly efficient microbial process that produces Pd nanoparticles (bio-Pd) with unique catalytic activity in the reductive precipitation of hexavalent chromium ions, both in pure cultures and under simulated sandy aquifer conditions. Both the formation kinetics and activity of these bioPd nanoparticles, which are produced by Clostridium sp. BC1 via the reductive precipitation of Pd (II) ions, contrast markedly with bioPd nanoparticles of comparable shape and morphology produced by Shewanella and Desulfovibrio [1, 2]. This presentation will describe the application of x-ray absorption spectroscopy (XAS) to investigate the structural basis for the different catalytic activities of these bioPd nanoparticles. Electron microscopy images of bioPd–loaded biomass show how Pd nanoparticles and nanoparticle aggregates are predominantly associated with the cell wall, but also occur within the cytoplasm. Transmission electron microscopy images did not resolve lattice spacings in any nanoparticles even though x-ray diffraction results indicate that crystalline nanoparticles form in all cases. Systematic changes in the lattice parameter of the different bioPd nanoparticles, however, are discernable in the extended x-ray absorption fine structure (EXAFS) region of XAS spectra. Once corrected for nanoparticle size, the EXAFS fit results show a lattice expansion in the catalytically active bioPd which is consistent with the presence of interstitial hydrogen [3]. This finding explains the unique catalytic activity and is consistent with the predominant bioPd synthesis pathways of the different microbial species. This work serves as an ideal case study of the potential applications of XAS to investigate structurereactivity relationships of both naturally-occurring and engineered nanoparticles in light of uncertainties in the coherence of particle size with the size of ordered domains within the nanoparticles themselves. [1] De Windt et al. (2005) Environ. Microbiol. 7(3), 314–325. [2] Lloyd et al. (1998) Appl. Environ. Microbiol. 64(11), 4607–4609. [3] Sun et al. (2006) Langmuir 22, 807–816.

Goldschmidt Conference Abstracts 2010

Sequestration of Cs by Na- and H-birnessite from pH 3 to 11 as measured with time-resolved synchrotron X-ray diffraction

A297

Untangling the true phylogeny of Leptothrix ochracea with single cell genomics and FISH E.J. FLEMING, 1* A.E. LANGDON1,2, R.S. STEPANAUSKAS1, N. POULTON1, D. MASLAND1 1 AND D EMERSON

CLAIRE R. FLEEGER1, PETER J. HEANEY2 3 AND JEFFREY E. POST 1

1

Department of Geosciences, Pennsylvania State University, University Park, PA 16802 USA ([email protected]) 2 Department of Geosciences, Pennsylvania State University, University Park, PA 16802 USA ([email protected]) 3 Department of Mineral Science, Smithsonian Institution, Washington, D.C. 20560 USA ([email protected]) Low-level nuclear waste storage tanks at the DOE Hanford site in Richland, Washington have leaked more than 1 million gallons of solution that is extremely basic (pH > 13) with high ionic strength and concentrated in radioactive Cs137 (2 x 1010 Bq/L, equivalent to 0.04 mmol/L). The underlying Ringold Formation consists of poorly consolidated clays, silts, and sands rich in Fe and Mn oxides, including the phyllomanganate birnessite. Interlayer cations in birnessite are highly exchangeable, and it has been demonstrated that millimolar concentrations of aqueous Cs+ will rapidly exchange for Na+ in the birnessite interlayer in neutral solutions [1]. For the first time, we have explored diadochic substitution of Cs+ for Na+ in birnessite over a wide pH range. The cation exchange products of in situ reactions are characterized with time-resolved synchrotron X-ray diffraction (TR-XRD) and inductively coupled plasma-mass spectroscopy (ICP-MS) at pH values ranging from 3 to 11. In these experiments, the rate of exchange of Cs+ for Na+ decreased as pH increased. However, the birnessite structure transformed from triclinic to hexagonal symmetry at pH 3. Thus, at low pH, aqueous H+ outcompeted with Cs+ and Na+ in partitioning into the birnessite interlayer. Hexagonal H-birnessite also readily exchanged interlayer H+ for Cs+ from pH 3 to 11, as revealed by in situ TR-XRD and ICP-MS. As with Na-birnessite, the rate of Cs+ cation exchange decreased with higher pH. A transformation of hexagonal H-birnessite to triclinic symmetry at pH 13 and 0.1 M CsOH is reported for the first time; the mechanism of this transformation has yet to be determined. [1] Lopano, Heaney & Post (2009) American Mineralogist 94, 816–826.

Bigelow Laboratory for Ocean Sciences, W. Boothbay Habor, ME 04543 (*correspondence: [email protected]) 2 Swarthmore College, Swarthmore, PA 19081 Leptothrix ochracea is noted for its ability to rapidly accelerate the biofouling of iron contaminated water systems by producing large masses of Fe-oxyhydroxide encrusted microtubular sheaths. For the past 120 years this bacterium has been regularly described in the scientific literature, always being noted for its association with freshwater iron seeps. Its taxonomy has been based solely on its morphology, and it is considered the type species for the Leptothrix genus. Despite this long history, L. ochracea has proven refractory to laboratory culture, and attempts to discover its true phylogeny have failed. The recent development of single cell DNA sequencing used in combination with florescence in situ hybridization (FISH) have finally made it possible to address L. ochracea’s phylogeny. Taking advantage of L. ochracea’s filamentous growth and sheath formation, flow cytometry was used to select sheath-associated cells from a freshly formed iron mat. After flow-cytometric isolation, genomic DNA from individual, cell-containing sheath particles was amplified using multiple displacement amplification (MDA). The MDA products were then used as templates in PCR-amplification and subsequent sequencing of the 16S rRNA gene (40 sequences obtained). Alternatively, environmental iron mats were sieved through 8 micron filters (to retain sheath material and enrich L. ochracea cells). The 16S rDNA gene sequences were obtained from the filters using cloning methods (65 clones total). Phylogenetic analysis identified a cluster of sequences (29%) that deduction suggested might be L. ochracea. These were related to other Leptothrix-Sphaerotilus spp, but were sufficiently divergent that a highly specific FISH probe (Lepto175) was developed that bound to canonical L. ochracea but not L. cholondii or S. natans. Use of this probe with freshly formed iron mats, indicated L. ochracea accounted for between 31%-85% of total bacteria. These data confirm the morphological identification of L. ochracea and suggest it belongs to a distinct clade of the Sphaerotilus-Leptothrix group. Obtaining the genome of L. ochracea will ultimately allow us to understand its physiology.

A298

Goldschmidt Conference Abstracts 2010

Constraints on the formation mechanism of early Solar System organic matter in primitive IDPs

Groundwater chemistry and the active bacterial community in a pristine confined aquifer

G.J. FLYNN1, S. WIRICK2, L.P. KELLER3, C. JACOBSEN2 4 AND S.A. SANDFORD

T.M. FLYNN, R.A. SANFORD AND C.M. BETHKE*

1

Dept. of Physics, SUNY-Plattsburgh, Plattsburgh NY 12901 USA ([email protected]) 2 Dept. of Physics and Astronomy, SUNY- Stony Brook, Stony Brook, NY 11794 3 NASA Johnson Space Center, Houston TX 77058 4 NASA Ames Research Center, Moffett Field, CA 94035 Chondritic, porous interplanetary dust particles (CP IDPs) are the most primitive samples of extraterrestrial material available for laboratory analysis [1]. The individual grains in these CP IDPs are coated by layers of carbonaceous material [2], typically ~100 nm thick, which holds the grains together. We analyzed these grain coatings by X-ray Absorption NearEdge Structure (XANES) spectroscopy [3]. The grain coatings in CP IDPs are organic and appear to have formed prior to the aggregation of the most primitive dust particles available for laboratory analysis, making the grain coatings the oldest surviving samples of the pre-biotic organic matter in our Solar System. The thickness and C-XANES spectrum for the coatings on all grains in an individual CP IDP are very similar, independent of the mineralogy of the underlying grain. This indicates that mineral specific catalysis (e.g. the FischerTropsch process), one widely accepted model for organic formation in the early Solar System, was not the production mechanism for the primitive organic matter coating the grains in CP IDPs. Our observations are consistent with the alternative model, that primitive organic matter was produced by irradiation of carbon-bearing ices that condensed on the grain surfaces. [1] Ishii et al. (2008) Science 319, 447–450. [2] Thomas et al. (1996) in Physics, Chemistry & Dynamics of Interplanetary Dust, ASP Conf. Series 104, 283–286. [3] Flynn et al. (2003) Geochim. Cosmochim. Acta 67, 4791–4806.

Department of Geology, University of Illinois, Urbana, IL 61801, USA (*correspondence: [email protected]) Iron-reducing and sulfate-reducing bacteria are widespread throughout anoxic aquifers, but the interplay of their activity with the chemistry of groundwater is poorly defined. We quantify how the distribution of active bacterial populations varies with the chemical composition of groundwater in the Mahomet aquifer of east-central Illinois. To sample actively growing microbes, we deployed in situ sediment traps in 19 wells across the aquifer. We then profiled the bacterial community using terminal restriction fragment length polymorphism (T-RFLP) and 16S rRNA gene libraries. Groundwater at each well had a concentration ratio of ferrous iron to sulfide of at least 10, indicating iron reduction should be the predominant bacterial process throughout the Mahomet. The molecular analyses revealed significant populations of sulfate-reducing bacteria growing alongside iron reducers, indicating sulfate reducers are not excluded by active iron reduction. We employed multivariate statistics to compare the structure of bacterial communities across the aquifer, then analyzed these results for correlations to concentrations in groundwater of ferrous iron, sulfide and sulfate. Ferrous iron and sulfide are commonly used as indicators of the nature of microbial activity in aquifers, but we observed no statistically significant relationship between bacterial community structure and the concentration of either ion. Communities in areas of high sulfate groundwater are more similar to each other than those from areas with low sulfate concentrations. Populations of the iron reducers Geobacter, Geothrix, and Desulfuromonas comprise 32-34% of the bacterial community in low sulfate areas, but only 18% in high sulfate areas. Areas with a greater abundance of iron reducers also have the highest measured sulfide concentrations, indicating sulfate reducers are most active there. These results argue the relationship between iron reducers and sulfate reducers may be not only competitive, but mutualistic.

Goldschmidt Conference Abstracts 2010

A299

Trace elements in olivines as probes of parental melt compositions in the western rift of East Africa

Reactions of accessory minerals during sub-solidus alteration of granitic rocks by As-rich fluids

S.F. FOLEY1, D.E. JACOB1 AND H.ST.C. O’NEILL2

H.%J. FÖRSTER1, M. ONDREJKA2* AND P. UHER3

1

Earth System Science Research Centre and Institute for Geosciences, University of Mainz, Germany ([email protected], [email protected]) 2 Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia Olivine is commonly the earliest abundant phase crystallizing in mafic igneous rocks, and therefore has the potential to record information about unfractionated melts. Distinguishing liquidus olivines from crystals with other origins is particularly important for MgO-rich rocks such as picrites, kimberlites, and olivine lamproites, for which the proportion of primary igneous olivines is debated. Olivine phenocrysts in ugandite (16-22wt% MgO) and leucite basanite from the western branch of the East African Rift [1] have been analyzed for up to 34 trace elements by Laser-ICP-MS with detection limits as low as 1ppb. Trace element concentrations are remarkably uniform between large and small phenocrysts; leucite basanites (Mg# 59) have higher DCa and DAl, and less fractionated LREE/HREE than MgO-rich ugandites (Mg# 75-80). Zonation is seen in elements with cation charges from 5+ to 2+ (P, Ti, Zr, Cr, Al, Sc, V, Cu, Mn, Ni) and may correlate with Ti and Al, but not P. Some early phenocryst cores have high Li or Ni, low Mn, or enrichments in many trace elements, whereas xenocrysts have exceptionally low Na, Cr, Ti, V and Co. Partition coefficients for Ni are 31-35, less than in lamproites [2], with which they demonstrate correlations with K2O, K2O/Al2O3 and K2O/Na2O in melt, but none with SiO2 content or Mg#. D-values for Cr, Mn and Co overlap with those of basalts, whereas those for Sc (0.011-0.018), Zn (0.44-0.49) and Ga (0.006-0.007) are lower. V/Sc indicates fO2 = 'FMQ – 0.54 to +1.38 at the time of olivine crystallization. A comparison of point analyses and line scans shows that line scan analyses are contaminated in Al, Ca, Cu, Ga, Sr, Zr, Nb, La and Ce, elements that are also concentrated in microcracks between subgrains, indicating smearing out during polishing, and demonstrating that large spot analyses produce the best results. [1] Rosenthal et al. (2009) Earth Planet. Sci. Lett. 284, 236– 248. [2] Foley & Jenner (2004) Lithos 75, 19–38.

1

Deutsches GeoForschungsZentrum-GFZ, Section Reservoir Technologies, D-14473 Potsdam, Germany 2 Dept. of Mineralogy and Petrology, Comenius Univ., Mlynská dolina G, 842 15 Bratislava, Slovak Republic (*correspodence: [email protected]) 3 Dept. of Mineral Deposits, Comenius Univ., Mlynská dolina G, 842 15 Bratislava, Slovak Republic In small zones in the apical part of the Zinnwald/Cínovec granite cupola (Germany/Czech Republic), consisting of highly evolved, weakly peraluminous topaz–albite–Li mica leucogranites of A-type affiliation, various As-bearing accessory minerals were identified. This assemblage includes REE arsenates [arsenoflorencite-(Ce), chernovite-(Y), hydrated chernovite-(Y)%xenotime-(Y) solid solutions] and As-bearing silicates (thorite, coffinite, zircon). Accompanying minerals comprise As-poor REE fluorocarbonates [bastnäsite(Ce), synchysite-(Ce), synchysite-(Y)], fluocerite-(Ce), and As-free ferrocolumbite. Arsenoflorencite-(Ce) contains low to moderate concentrations of P, Pb, and Sr (4.0–8.3 wt% SrO), reflecting substitution of florencite, arsenoflorencite, goyazite, and kintoreite components. Relative to published data, chernovite-(Y) from this location is the most REE-rich yet recorded, with up to 0.51 apfu REE substituting for Y. Thorite, coffinite, and zircon accomodated maximum concentrations of As of 14.4, 5.3, and 1.3 wt% As2O5, respectively. Most of these minerals display variably kinked REECN pattern, reflecting the lanthanide tetrad effect. Formation of the Asrich minerals appears confined to zones, where the granite became infiltrated by post-magmatic, probably hydrothermal As-rich fluids. A tentative model is provided which tries to explain the origin of these minerals by dissolution%reprecipitation and alteration of pre-existing granitic accessory minerals. Our observations corroborate the results of previous studies demonstrating that As-bearing fluids are susceptible to dissolve and severely alter primary and secondary REE–Y–Th–U–Zr minerals. This work was supported by the Slovak Research and Development Agency under contract No. APVV-0557-06 and APVV-0279-07.

A300

Goldschmidt Conference Abstracts 2010

Arsenic association with secondary iron phases on ferroan micas: Implications for ground water quality in South Asia

Plutonic imaging of two Proterozoic underplating events in the NW Wyoming Province from Hf-Isotopes of zircon from Cretaceous Batholiths

A.L. FOSTER1*, H.A. LOWERS2, G.N. BREIT2, J. WHITNEY2, J. YOUNT2, M.N. UDDIN3 3 AND A.A. MUNEEM

D.A. FOSTER1, P.A. MUELLER1, A.L. HEATHERINGTON1, G.D. KAMENOV1 AND J.N. GIFFORD1

1

USGS, 345 Middlefield Rd.. MS 901, Menlo Park, CA 94025, USA (*correspondence: [email protected]) 2 USGS, Box 25046, Federal Center, MS 964, Denver CO, 80225, USA ([email protected], [email protected], [email protected], [email protected]) 3 Geological Survey of Bangladesh We analyzed a variety of fresh (river) and ancient (aquifer) sediments from Nepal and Bangladesh using chemical extraction, electron microbeam and synchrotron Xray techniques in order to track the evolution of arsenic (As) speciation from recent to buried sediment and to determine the predominant geochemical reactions controlling As solubility in Bangladesh ground water. The sediments represent a range of weathering states and redox conditions, and were collected from several sites. We and others have previously reported that mica separates from the study area contain 2-3 times more As than the bulk sediment [1, 2]. µ-XRF analysis further indicates that As is almost always associated with iron-rich micas (biotite, altered biotite, and chlorite) rather than muscovite. However, the apparent As enrichment of iron micas is largely due to secondary As-bearing phases that coat mica surfaces or penetrate prominent clevage planes, rather than direct incorporation of As into the mica structure. In oxidized river sediments and shallow soil, As5+-bearing ferric (hydr)oxides form within and on micas; gray, reducing sediment contains As3+-bearing siderite and vivianite on micas. Growth of arsenian pyrite on/in ferroan micas occurs in sulfidic sediment [3]. The transformation from ferric to ferrous As-bearing phases could have implications for As release to ground water. The preferential formation of As-bearing, Ferich secondary phases on Fe-micas over other minerals also needs investigation; Fe-micas may posess favorable electrochemical properties, for example. We conclude that the stability of both ferric and ferrous iron phases must be considered when modeling the release of As to ground water in South Asia. [1] Foster et al. (2000) EOS Trans. AGU Fall Mtg. Suppl. 81, absract H21D-01. [2] Dowling et al. (2002) Wat. Res. Research 38, 1173–1190. [3]. Lowers et al. (2007) GCA 71, 2699–2717.

Department of Geological Sciences, University of Florida, Gainesville, Florida 32611 USA ([email protected]) Plutonic imaging refers to the extraction of discrete elemental and isotopic (U-Pb, Hf, O, etc.) information from in situ measurements of individual zircons and other accessory minerals as a complement to secondary isotopic systematics of plutonic rocks. It can provide critical constraints on crustmantle intereactions and an image of the distribution of temporally and compositionally distinct lithospheric components. Plutonic imaging provides a critical complement to geophysical studies that cannot provide estimates of crustal age diversity and true composition. The Late Cretaceous (ca. 70 Ma) Pioneer, Philipsburg, and Mt. Powell batholiths were emplaced along the boundary between the Archean Wyoming craton and ProterozoicArchean Great Falls tectonic zone. Hf-isotopes of magmatic zircons from granodiorite and tonalite from the Pioneer batholith give "Hf values for most grains of -28 to -32 with depleted mantle model ages of 1.8-2.0 Ga. The dominant population of magmatic zircons from the Mt. Powell and Philipsburg plutons gives "Hf of -16 to -20 along with a few grains that extend the overall range from -12 to -30. Single stage model ages for the -16 to -20 group are 1.4-1.6 Ga, other grains range from 1.1 to 1.9 Ga. These data are consistent with derivation of these metaluminous batholiths from partial melting of two discrete, but likely mafic, lower crustal sources, one that is mainly Paleoproterozoic (ca. 1.9 Ga) and the other Mesoproterozoic (ca. 1.5 Ga). The Pioneer batholith plutons were largely derived from partial melting of Paleoproterozoic crust similar in age to the Little Belt magmatic arc of the Great Falls tectonic zone, whereas the Philipsburg and Mt Powell batholiths were derived mainly from mafic rocks emplaced during the formation of the ca. 1.47 Ga Belt Basin. These data suggest that the thick (~20 km) mafic (P-wave velocities >7 ms-1) lower crust of the Wyoming province and Great Falls tectonic zone is diachronous and significantly younger than the Archean-Paleoproterozoic upper crust. This implies that the lower crust along the northwestern margin of the Wyoming craton was underplated (either tectonically or magmatically) subsequent to the formation of the Archean upper crust of the Wyoming craton.

Goldschmidt Conference Abstracts 2010

A301

Yellowstone microbes, heated corals and their global connection

Tritium/Helium-3 dating of groundwaters around Chernobyl site

B.W. FOUKE

E. FOURRE1*, P. JEAN-BAPTISTE1, A. DAPOIGNY1, D. BAUMIER1, D. BUGAI2, L. AQUILINA3, T. LABASQUE3, C. LE GAL LA SALLE4 AND J. LANCELOT4

Department of Geology, University of Illinois UrbanaChampaign, Urbana, IL 61801 USA (*correspondence: [email protected]) A decade of coordinated Systems Geobiology research on Yellowstone hot springs and Caribbean and Pacific coral reef ecosystems indicates a host of striking scientific parallels. The spring water at Mammoth Hot Springs in northern Yellowstone is derived from rain and snowmelt runoff in the Gallatin Mountains that flows down along faults into the rock subsurface. This groundwater is then heated by the Yellowstone supervolcano to ~100¡ C (212¡ F), chemically dissolves deeply buried ~350 million year old marine limestone, and flows back up to the surface to emerge from vents at a temperature of 73¡ C (163¡ F). During this hydrologic journey, the Mammoth Hot Spring water evolves a salty chemical composition remarkably similar to that of seawater. Furthermore, the limestone rock (called travertine) that precipitates to form the classic meter-scale terraced steps of Mammoth Hot Springs are composed of a form of calcium carbonate (CaCO3) mineral called aragonite. This is the same mineral that corals use to precipitate and grow their skeletons. In addition, several of the microbes that we have identified in the 73 to 25¡ C (163 Ð 77¡ F) hot-spring vent drainage patterns at Yellowstone are similar, and sometimes identical, to the microbes inhabiting coral tissues, coral mucus and seawater. As a result, our field-based controlled experiments at Yellowstone are now being used to predict how corals will respond to future global warming. Heat-loving (thermophilic) microbes living at 65 to 71¡ C in Yellowstone are able to respond to shifts in water flow rate and temperature by changing the speed at which travertine rock (aragonite) is deposited on the floor of the drainage channels. Our biochemical analyses suggest that the microbes do this by producing different types of protein under different water temperature and flow conditions. We are now applying this mechanism derived from Yellowstone to form new interpretations of how density banding in the aragonitic skeleton of scleractinian corals (similar to tree rings) reflects coral response to changing sea surface temperature. Accurate interpretation of coral skeleton density banding is critically important for predicting future changes in sea surface temperature and thus plays a central role in shaping long-term policy strategies on global warming.

1

LSCE, CEA-CNRS-UVSQ/IPSL, 91191 Gif sur Yvette, France (*correspondence: correspondence: [email protected]) 2 Institute of Geological Sciences, Ukraine 3 GŽ osciences Rennes, UMR 6118, 35000 Rennes, France 4 GIS/CEREGE, N”mes University, France Estimates of groundwater age allow geohydrologists to calculate recharge rates, assess aquiferÕ s contamination risks, and calibrate complex flow models. The 3H/3He dating method offers a direct measure for the time since groundwater had its last gas exchange with the atmosphere. The aim of this study is to bring temporal constraints to the radionuclide transport model in the Chernobyl test site. Samples have been collected in the exclusion zone, close to a trench filled with low-level wastes, both in the upper eolian sand layer and deeper in the alluvial deposit. CFCs and SF6 have been measured as well in order to compare dating methods. The 3H/3He results presented in Figure 1 clearly show increasing ages with depth (below groundwater table). This fully supports the groudwater stratification developed in the hydrogeological model of the area. The infiltration recharge rate is a sensitive key parameter of the model, and our data are consistent with a rate about 200mm/yr (maximum estimate).

Figure 1: 3H / 3He ages versus depth below groundwater table.

A302

Goldschmidt Conference Abstracts 2010

Oxidation of organics under hydrothermal conditions: Implications for the evolution of methane on Mars

Fe(II) uptake and transformation on uranium contaminated sediment from the Rifle IFRC field site PATRICIA M. FOX1*, JAMES A. DAVIS1 2 AND RAVI KUKKADAPU

D.I. FOUSTOUKOS1 AND J.C. STERN2 1 1

Geophysical Laboratory, Carnegie Institution of Washington, DC 20015 ([email protected]) 2 NASA Goddard Space Flight Center, Code 699, Greenbelt, MD 20771 ([email protected])

To assess the effect of strong oxidants on the evolution of organics on Martian environments, a series of experiments have been conducted involving decomposition of dissolved HCOOH (aq) utilizing H2O2 (aq) at low temperature hydrothermal conditions (80-150°C, 25 MPa). Results clearly indicate the significantly enhanced kinetic rate of decarboxylation process relative to the homogeneous HCOOH-H2O system, with even greater oxidation effects imposed when Fe-oxides (e.g. Fe3O4) catalyze the reaction. The later might be closely related to formation of metastable hydroxyl radicals through Fenton type reactions enforced by H2O2 decomposition in presence of Fe+2 phases. Moreover, the !13C isotopic composition of the evolved HCOOH (aq) shows a kinetic isotope effect that could be used as a proxy to distinguish low-temperature abiotic oxidation from biotic or other abiotic processes occurring at higher temperatures. To further evaluate CH4 (aq) oxidation processes, we have also investigated the kinetic rate of abiotic methane oxidation in the CH4-O2-H2O system at subseafloor hydrothermal conditions (200-350°C, 30 MPa). Results indicate that complete CH4 oxidation to CO2 proceeds in significantly lower kinetic rate than the decomposition rates of intermediate carbon species (e.g. HCHO, CH3OH, HCOOH). Experimental results also reveal formation of metastable species such as dissolved CO (aq) and H2 (aq). Thus, it appears that partial CH4 (aq) oxidation might occurred leading to release of H2 (aq) which is incorporated into the water-gas-shift reaction to form metastable CO (aq). Both species are present only at the very early stages of the experiments suggesting that strongly disequilibria conditions might be responsible for triggering partial CH4 (aq) oxidation. Most importantly, our data suggest that the rates of oxidation process approximate the extent of CO2 (aq) conversion to CH4 (aq) even when it’s Fischer-Tropsch catalyzed at an ultimate rate by Ni-Fe alloy under highly reducing conditions. This has important implications on carbon cycling and the habitability of hydrothermal environments associated with the anoxic/oxic boundaries established during hydrothermal circulation especially within the highly oxidizing Martian upper crust.

US Geological Survey, 345 Middlefield Rd. MS 496, Menlo Park, CA 94025 (*correspondence: [email protected]) 2 Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, MS: K8-96, PO Box 999, Richland, WA 99352

In the course of biostimulation experiments designed to remediate subsurface uranium contamination through the creation of reducing conditions at the Rifle IFRC site, iron reduction by native bacteria produces large quantities of Fe (II) in the aquifer. Dissolved Fe (II) concentrations typically reach levels of 50-100 µM before the onset of sulfate reduction. The goals of our experiments were to investigate the degree and mechanism of Fe (II) uptake on Rifle sediments and the possibility of abiotic U (VI) reduction in the Rifle aquifer. Results from a tracer test in which Fe (II) amended groundwater was injected into multi-level sampling wells in the Rifle aquifer indicated that Fe (II) uptake by the sediments is extensive. In addition, decreases in dissolved U (VI) were observed in the aquifer after injection of a pulse of pH 8.4 groundwater, but not at the ambient pH value of 7.2, indicating that abiotic U (VI) reduction in the presence of Fe (II) may be important at higher pH. Results from a series of laboratory experiments performed over a range of chemical conditions (Fe (II) concentration and pH) are presented along with Mossbauer data collected on selected sediment samples. Mossbauer results indicate that a fraction of the Fe (II) added to sediments is oxidized to Fe (III) on mineral surface. Results from these field and laboratory experiments indicate that the sediment can take up very large quantities of Fe (II), and thus the dissolved Fe (II) represents only a fraction of the pool of Fe (II) in the aquifer. In addition, abiotic U (VI) reduction may be more favorable in the Rifle aquifer at higher pH values.

Goldschmidt Conference Abstracts 2010

Melting the hydrothermally altered sheeted dike complex: Chemical composition of the main MORB crustal contaminant 1,2,4

1

2

L. FRANCE *, B. ILDEFONSE , J. KOEPKE , M. GODARD1 AND C. MACLEOD3 1

Université Montpellier 2 / CNRS, France (*correspondence: [email protected]) 2 Leibniz Universität Hannover, Germany 3 Cardiff University, UK 4 Now at University of Cergy-Pontoise, France Recent studies on fossil (Oman ophiolite) and modern oceanic crust (IODP Hole 1265D) shed light on interactions between the magmatic and the hydrothermal systems at fast spreading ridges [1, 2]. It is shown that the interface between the mostly liquid melt lens and the sheeted dike complex (SDC) is a dynamic system; the top of the melt lens can migrate vertically with the potential to reheat, to trigger hydrous partial melting, and to assimilate the hydrothermally altered SDC. It is proposed that the occurrence of recrystallized granoblastic dikes and plagiogranitic intrusions at the base of the SDC results from these processes. The newly formed hydrous melt represents the main crustal contaminant for the MORB-type melts filling the melt lens. To test this model, we performed hydrous partial melting experiments using an IHPV under conditions (P-T, redox) that match those prevailing at the base of the SDC, and using a natural, fully altered diabase as starting material. Major and trace element compositions of experimental melts & minerals are compared to those of natural plagiogranites and of granoblastic dikes. Generated melts are water saturated, transitional between tholeiitic and calc-alkaline, and match the compositions of plagiogranites intruding the base of the SDC. Newly crystallized minerals have compositions that are characteristic of granoblastic dikes. REE and other trace element contents match those of natural oceanic plagio-granite. Analyses of the degassed experimental products allow us discussing the fluid affinity of various elements. Our studies demonstrate that hydrous partial melting is a likely common process at the base of the SDC, starting at temperatures above 850°C. It supports a residual origin for granoblastic dikes, an anatectic origin for the associated plagiogranites, and it is consistent with dynamic models for the magmatic / hydrothermal transition. Hydrous partial melting must play a significant role in the contamination and geochemical variability of MORBs. ! [1] Koepke et al. (2008) doi:10.1029/2008GC001939. [2] France et al. (2009) doi:10.1029/2009GC002652

A303

Mountain versus floodplain weathering: Example of the Himalayan basin CHRISTIAN FRANCE-LANORD AND MAARTEN LUPKER CRPG-CNRS, BP20, 54501 Vandoeuvre-les-Nancy, France Mountain building is generaly considered as a triggering factor of weathering as steep slopes promote physical erosion creating reactive surfaces that tend to facilitate weathering. On the other hand, mountains also promote fast transport that reduces particle residence time and therefore limit reaction. Here we present an analysis of modern river sediment compositions from the Ganga river basins in Himalaya and the Ganga floodplain. River sediment geochemistry is compared to average source rocks in the Himalaya tacking into account their variability. River sampling allows to track the evolution of sediment geochemistry from the head basins in Himalaya throughout their course in the floodplain. Sampling also includes depth profiling of the river sediments that reflect the effects of mineralogical sorting. This tend to enrich surface suspended load in fine grained / clay rich particles whereas bed-sediments tend to concentrate in coarser and quartz rich particles, the fine grain end-member being the most sensitive to weathering. The data show a clear depletion in mobile elements such as Na and K from sources to the Bangladesh delta while Ca and Mg chemistry is dominated by carbonate dissolution. The budget is however hampered by sources effects such as input from (1) southern tributaries of the Ganga that are originaly very depleted in Na and K or (2) the Siwaliks sediments, i.e. former floodplain sediments, that are strongly depleted in Na. Taking into account these sources allows to refine the distribution of weathering. Consistently with the trends observed on dissolved river chemistry, Na is the main species released from silicate weathering in the basin. Comparison of Himalayan river sediments with source rocks from either High Himalaya of Lesser Himalaya (LH) suggest that there is no detectible losses in K during mountain weathering. For Na the budget is more difficult as LH formation is more depleted in Na than river sediments. Depending on proportion of LH in the source rocks, the apparent Na leaching in the mountain environment represent 15 to 0% of the initial content. Floodplain leaching is much more intense and about 50% Na and 30% K is lost in this compartment. The floodplain may appear less favorable to weathering than the mountains as water availability and drainage are lower. On the other hand temperature and long residence time in the floodplain favour more intense weathering than in the mountains.

Goldschmidt Conference Abstracts 2010

A304

The growth of organic nanoparticles defined by boehmite-resorcinol complexation

Self-organizing maps for targeting within regional geochemical data sets S.J. FRASER1*, B.L. DICKSON2, P. KOWALCZYK3 1 AND J.H. HODGKINSON

MARTINA FRANKE 1

Department of Soil Science, University of Trier, D-54296 Trier, Germany ([email protected]) Boehmite ((-AlOOH) can form complexes with resorcinol (m-dihydroxybenzene) in which a growth of organic nanoparticles was observed. The organic coatings from the resorcinol-boehmite complex showed very compact flakes in structure and covered the entire fine mineral surface. In contrast, boehmite comprised of orthorhomic structures. The complex was synthesized by adsorption in a gas-solid phase at 50 °C in the presence of atmospheric pressure for a period of 60 days in total darkness. In this study, a comparative structure analysis was conducted from boehmite and resorcinol-boehmite complex by using methods of VNIR spectroradiometry, Fourier transform infrared (FTIR) spectrometry, energy dispersive X-ray spectrometry (EDX), scanning electron microscopy (SEM), and atomic force microscopy (AFM). AFM images in contact mode showed compact crosslinked structures of organic nanoparticles and nanopores. The growth of organic nanoparticles was reduced in the presence of stabilizing mechanisms which occurred by the complexation. However, the polymerization of resorcinol was more intensive and located on the upper surfaces. The mhydroxy groups of resorcinol showed favorable reactions to this complexation. It was clear that stereochemical effects were of significant relevance in defining the interactions between resorcinol and boehmite.

CSIRO MDU, PO Box 883, Kenmore, 4069 Australia (*correspondence: [email protected]) ([email protected]) 2 Dickson Research Pty. Ltd., 47 Amiens St, Gladesville, 2111 Australia ([email protected]) 3 PK Geophysics Inc., 14717 16A Ave, Surrey, BC, Canada V4A 5M6 ([email protected]) We report on various self-organizing maps (SOM) [1] visualization approaches that can be used to identify targets, trends and relationships in regional geochemical data sets. These visualization approaches include (1) use of quantization errors, (2) K-means clustering of SOM-derived nodes, (3) ‘cluster-normalized’ element anomaly (spatial) maps, (4) component plots, and (5) cross-plots of selected elements based on SOM-node values. While SOM can be used to assist in the analysis and visualization of regional geochemical data, it is the spatial context and coherence of the samples that SOM identifies, which are critical for their assessment. Spatial plots of samplelocations, which are colour-coded by either their K-means node cluster colour or by the magnitude of their quantizationerror, can be used to rapidly assess the significance of samples identified as anomalous. Examples will be presented from a study involving analysis of stream and lake sediment analytical data over part of the Quesnellia Terrane of central British Columbia [2]. The input dataset consists of some 15, 000 samples, each with 42 elemental values that were extracted from levelled and imputed elemental grids [3]. [1] Kohonen (2001) Self-Organizing Maps, 3rd edn, SpringerVerlag, Berlin, p.501. [2] Fraser & Hodgkinson (2009) Geoscience BC Report 2009–14. [3] Barnett & Williams (2009) Geoscience BC Report 2009–003.

[1] Franke M. (2002) diploma thesis, University of Trier, 187.

Goldschmidt Conference Abstracts 2010

Low temperature porosity preserving microquartz from Upper Cretaceous sandstones of the Subhercynian Basin (Germany) 1 ,

2

M.W. FRENCH * R.H. WORDEN, E. MARIANI , W.C. HORN, C.E. KLIEWER, W.A. LAMBERTI, R.R. MUELLER3 AND C. FISCHER4

A305

Investigating the metastability and nanomineral properties of synthetic and natural schwertmannite R.A. FRENCH, M. MURAYAMA AND M.F. HOCHELLA JR. Department of Geosciences, 4044 Derring Hall, Virginia Tech, Blacksburg, VA 24061 USA (*correspondence: [email protected])

1

ExxonMobil Upstream Research, Houston, TX 77027 Univ. of Liverpool, Liverpool, United Kingdom 3 ExxonMobil Research & Engineering, Clinton, NJ 08801 4 Univ. of Goettingen, Goettingen, Germany 37073

2

Microquartz found in Late Santonian age sandstones in the Heidelberg Formation in Germany occurs in multiple episodes and preserves porosity by inhibiting syntaxial quartz overgrowths. Characterizing the microquartz and understanding the growth mechanisms can be applied to developing an understanding of porosity preserving microquartz in deep clastic reservoirs. Electron Backscatter Diffraction (EBSD) indicates at least three episodes of microquartz adjacent to completely syntaxial cemented sandstones and porous sandstones within several meters laterally. EBSD analysis also indicates the microquartz is misoriented with respect to the detrital sandstone grains, while the syntaxial quartz inherits the crystallographic orientation of the detrital grains. EBSD data also indicates that although the microquartz is misoriented, there is some control on the microquartz growth. Transmission Electron Microscope (TEM) indicates multiple phases of silica which are related to microquartz growth. Wavelength Dispersive Spectroscopy (WDS) indicates variations in trace elements in the microquartz, which could be related to variations in fluid composition during growth. Integrating the results from these analytical techniques has helped us develop our understanding of the processes controlling microquartz and improved our ability to reconstruct the diagenetic history of porosity preserving microquartz.

Schwertmannite, an iron oxyhydroxide sulfate nanomineral, plays a significant role in the geochemistry of acid mine drainage (AMD) as a metastable phase with respect to goethite and by retaining toxic metals, e.g. arsenic [1]. Schwertmannite’s characteristic morphology is needles 100300 nm long and only 5-10 nm in diameter extending from a dense aggregate; varying temperature and time during schwertmannite syntheses result in distinctive morphological variation. The transition from the ‘pin-cushion’ morphology of schwertmannite to acicular nanogoethite particles was also monitored using scanning electron microscopy and x-ray diffraction. Natural samples of schwertmannite from the Iberian Pyrite Belt in Southwest Spain were investigated using high resolution transmission electron microscopy. Lattice fringes revealed that localized crystalline areas may exist in a highly disordered matrix to form the schwertmannite needles (Fig. 1). The atomically rough needle surfaces suggest that schwertmannite contains a high density of active surface sites.

Figure 1: An individual needle on a natural schwertmannite particle. Scale bar = 5 nm. [1] Acero et al. (2006) GCA 70, 4130–4139.

A306

Goldschmidt Conference Abstracts 2010

Biochemistry of metal interactions with Shewanella putrefaciens cytoplasmic membranes

Determination of trace elements in seawater by ICP-SFMS after Tm addition and co-precipitation

S. FRENCH AND S. GLASAUER*

N. FRESLON1,2,3, G. BAYON1, D. BIROT1, C. BOLLINGER2,3 2,3 AND J.A. BARRAT

School of Environmental Sciences, University of Guelph, Guelph ON, N1G 2W1 Canada (*correspondance: [email protected]) Gram-negative bacterial cell walls are chemically diverse, component-rich structures. The inner cytoplasmic membrane contains embedded proteins necessary for molecular and ion transport, cellular respiration, cell division, amongst other essential functions for cell survival and proliferation. Soluble metals produced during dissimilatory metal reduction can penetrate into Gram-negative periplasm and saturate the cytoplasmic membrane [1]. Shewanella putrefaciens CN32 was grown in the presence of 1 mM Mn2+, V4+, and U6+ ions under both atmospheric conditions as well as anoxia, and the lipid chemistries of the cell membranes were subsequently characterized. Metal speciation was confirmed through scanning transmission Xray microscopy (STXM) using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Changes in fatty acyl-chain chemistries across metal treatments were subtle and statistically insignificant, although varied significantly across changes in oxygen status. While the metal-induced variations were subtle, drastic changes are not necessary to invoke variations in phase-state chemistry in prokaryotes. It was observed that gel-to-fluid-gel phase transition temperatures increased significantly in anaerobic environments, suggesting a fluidizing effect of atmospheric exposure, and was confirmed through spectrofluorometric lipid microviscosity quantifcation. Alternatively, phospholipid liposomes were generated from CN32 cells grown both aerobically and anaerobically. The lipid diffusion in these structures was assessed using a pyrene derivative, which forms excimers when embedded in an ordered environment such as within a membrane. Lipid diffusion was observed to vary depending on metal treatment with 1 mM Mn2+, V4+, and U6+. It is believed that the variations in lateral lipid diffusion are due to cross-linking by the soluble metal cations. Combined with the observation that more thermal energy in these cases is necessary to induce lipid phase-state transition, this suggests that the products of dissimilatory reduction may have more of a role in preserving membrane integrity in situ than originally believed. [1] Beveridge, T.J. (2005). J. Nucl. Radiochem. Sci. 6: 7-10.

1

Département Géosciences Marines, IFREMER, Plouzané, France 2 Université Européenne de Bretagne, 35000 Rennes, France 3 Université de Brest, IUEM, CNRS UMR6538, 29280 Plouzané, France

We report on two novel procedures for the determination of several trace elements in seawater, including elements characterized by very low abundance (sub-0.1 to 1 ng l-1) in the ocean, such as REEs, Hf, and Th. Our methods are based on the procedure developed recently by Bayon et al. [1], and applied successfully to a wide range of geological samples. It involves addition of a Tm spike and pre-concentration using co-precipitation, prior to analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The addition of a small amount of Tm to the sample produces a positive Tm anomaly in the resulting REE pattern, which allows calculation of precise trace element concentrations. Two different procedures were investigated during the course of this study: 1) co-precipitation onto iron hydroxides (after addition of a Fe-spike); and 2) magnesium co-precipitation (no spike required). The validity of the procedures was assessed through a series of co-precipitation experiments, using ultra-diluted solutions of a certified rock standard (BIR-1), and analyses of natural water certified reference materials (CRMs). Results obtained for NASS-5, CASS-4, and SLEW-3 are in agreement with published working values for REEs. A set of proposed values for these CRMs, with uncertainties typically better than 8% (RSD), is also proposed for Hf, Zr, and Th. The advantages and disavantages of using the iron vs magnesium co-precipitation procedure for determining trace element concentrations in seawater will be compared and discussed. [1] Bayon et al. (2009) Geostand. Geoanal. Res. 33, 51–62.

Goldschmidt Conference Abstracts 2010

Luminescence of opals: A witness to their geochemistry

Turnover of mineral-free and mineral-associated organic matter in a soil warming experiment in Northern Sweden

E. FRITSCH1, E. GAILLOU1,2, F. MASSUYEAU1 3 AND B. RONDEAU 1

Universite de Nantes-CNRS, Institut des Matériaux Jean Rouxel (IMN) – UMR 6205, 2 rue de la Houssinière, BP 32229, 44322, Nantes Cedex 3, France (*correspondence: [email protected]) 2 Smithsonian Institution, NMNH, 10th and Constitution NW Washington DC 20560-0119 3 Université de Nantes-CNRS, LPGN - UMR 6112 There are two main features seen commonly in the ultraviolet luminescence of gem opals, one being a blue emission, the other a green one. The blue is due to a combination of two emissions with maxima at 414 and 460 nm coming from intrinsic, surface-related silica defects. The green one results from uranyl emission, if U concentration exceeds about 1 ppm. Both can be quenched by iron, if there is more than 2000 ppm present [1]. The blue luminescence of most gem opals is explained by the low levels of iron and the virtual absence of uranium in some sedimentary deposits, such as those of southern Australia. By contrast, volcanic deposits provide opals that are either inert due to their high Fe content, or fluoresce green, because of the presence of uranium. Uranium luminescence is often seen in common opal, but is almost inexistent in gem opals exhibiting diffraction of visible light. [1] Gaillou et al. (2008) Ore Geology Reviews 34, 113–126.

A307

MATS FRÖBERG1*, CHARLOTTE BRYANT2 1 AND DAN BERGGREN KLEJA 1

Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7001, SE 750 07 Uppsala, Sweden (*correspondence: [email protected]) 2 NERC Radiocarbon Facility (Environment), Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride, Scotland, G75 OQF, United Kingdom After 14 years of experimental soil warming in a Spruce forest in Northern Sweden, soils were sampled in autumn 2009. Density fractionation of the E and B horizons separated soil particles into light (mineral-free) and heavy (mineralassociated) organic particles. 14C analyses were made on the different fractions and on O horizon soil samples, with the aim of studying how experimental warming had affected different soil pools. The results from the density fractionation and 14C analyses will be presented.

A308

Goldschmidt Conference Abstracts 2010

U-Pb discordance in Archean detrital quartzites, central Wyoming: Implications for Pb loss mechanisms C.D. FROST1, C.M. ALLEN2, S. SWAPP1 AND B.R. FROST1 1

Geology and Geophysics, University of Wyoming 82071 (*correspondence: [email protected]) 2 School of Earth Sciences, Australian National University, Canberra, ACT

Precise, concordant U-Pb dates on zircon are maximized by a number of strategies, including careful selection of undamaged, clear grains; removal of a thin high-U surface layer by abrasion; and spot analysis to avoid fractures or altered domains. However, when analyzing detrital zircon populations one cannot select only the least damaged zircon grains without biasing the resulting age spectra. In this study, we examine U-Pb data from detrital zircon in Archean quartzites obtained by LA-ICP-MS. Although the samples come from a single metasedimentary package they exhibit dramatically different Pb loss behavior. We investigate the causes of Pb loss in these samples and the implications for Pb loss mechanisms in detrital zircon generally. Some detrital zircon populations from Mesoarchean quartz-rich paragneisses of the Sacawee block, central Wyoming Province, are dominated by concordant zircon that define a prominent age peak at 3.3 Ga. Others, despite comparable mean U contents and similar age, yielded almost exclusively discordant grains. Discordia define strongly linear chords with Cenozoic lower intercepts. Degree of discordance in these zircon grains correlates with U content. Discordant U-Pb ages of zircon in Archean metasedimentary rocks may be the result of Pb loss by volume diffusion if they are held at near-surface T for times of ~1 Ga. Thus those samples with concordant zircon may have remained buried whereas the others were nearer the surface and experienced diffusive Pb loss. However, the spatial distribution of the samples and the lack of identifiable structures that could have brought samples to the surface from different depths makes this explanation questionable. Alternatively, the Pb loss may be related to Eocene fluidrock interaction that removed ~75% of the U from the Archean rocks to form roll-front uranium deposits in the adjacent basins. We note that the quartz-rich paragneisses with concordant zircon also contain cordierite, which would have altered in the presence of fluids. We conclude that hydrothermal alteration was partitioned: some rocks were unaffected, but fluid interaction in others caused significant Pb loss. The presence of readily altered phases can usefully guide detrital zircon sample selection.

Si and O in the Earth’s core and their effects on the metal-silicate partitioning of other siderophile elements D.J. FROST1, K. TSUNO, D.C. RUBIE1 AND Y. NAKAJIMA1 1

Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, D95447, Germany ([email protected]) 2 Department of Earth Sciences, Rice University, 6100 Main Street, MS-126, Houston, TX 77005, USA ([email protected])

Oxygen and silicon are both potential light elements in the Earth’s outer core. At the liquidus temperature of the mantle at 1 bar, O and Si are mutually exclusive in Fe metal, as the Si content of the metal only starts to increase at low oxygen fugacities where the O concentration has already dropped to low levels. Experiments show, however, that at lower-mantle pressures, the combined concentrations of O and Si in Fe metal can increase to percent levels at silicate liquidus temperatures. O and Si interact strongly in liquid Fe and our results show that the presence of O in liquid Fe causes Si to become more siderophile. Consequently, the Si metal-silicate partition coefficient becomes less dependent on oxygen fugacity at high pressures, which would enhance the partitioning of both O and Si into core-forming Fe. We use a thermodynamic model to explore the partitioning of O and Si between the mantle and core at the present core-mantle boundary. The partitioning of O into liquid Fe is also found to influence the metal-silicate partitioning of other elements. In particular we have examined metal-silicate partitioning of alkali metals at conditions where significant O also enters liquid Fe. Experiments were performed with both 0 wt% and 5% S in the liquid Fe. The Rb/Cs ratio of the silicate Earth is higher than that of carbonaceous chondrites and one explanation is that this results from partitioning of Cs into Earth’s core. Our results indicate that metal-silicate partition coefficients for alkali metals increase down the group and with increasing pressure, temperature and metal S-content. Given the trends observed in these experiments it is plausible that the fractionation of Rb and Cs observed in the bulk silicate Earth results from core-mantle equilibration at pressures exceeding 25 GPa. Many previous studies have examined K partitioning between Fe-metal and silicate as there are important implications for the core’s heat budget if it contains significant concentrations of the radioactive isotope 40K. We use our partitioning data along with the Rb/Cs ratio of the Earth to place constrains on the maximum K content of the core.

Goldschmidt Conference Abstracts 2010

A309

The discovery and geological significance of Yanchang formation in South-Eastern Ordos basin

Transcriptional analysis of the response to supersaturated silicic acid in Thermus thermophilus

GUOMIN FU1, TIANJIN ZHANG2 AND SUNLEI3

Y. FUJINO1,2, T. OHSHIMA1, T. YOKOYAMA1 1 AND K. DOI *

1

Geoscience and Resources Institute, Chang’an University, Xi’an 710054, China (*correspondence: [email protected]) 2 Energy Institute,Yan’an University,Yan’an 716000, China ([email protected]) Yanchang formation was a main oil bearing series in Ordos basin of China. It was the superimposed and connection sand body was the major hydrocarbon migration pathway.However the pathways septated by thick muddy barrier or low permeability reservoir far away from source rock can not be explained. In this reason, partical researchers put forward that cracks were also the main hydrocarbon migration pathways, however lacking of direct evidence. It developed vertical fractures at Yanchang formation of Ying16 well. By observing the calcite vein samples under microscope, found it contained plenty of boiling hydrocarbon inclusions, including inorganic salt water, liquid and gas phase hydrocarbon inclusion which existed in hydrocarbon inclusion combinations, whose filling degree were different, the liquidphase as the major and gas-liquid ratio from 1.6 % to 3%, the size mostly from 8 to 12%m, shape consistent with motion state, regularly arrangement, as they were all boiling unstopped. During heating test, the homogenization temperature was Fahrenheit 90, salt degree from 1 0.2%to 1 8.45 %. By Using laser Raman spectroscopy, gas phase was without H2O, and the content of total hydrocarbons ()Ci) was 23.5%, methane content 6.7% occupied 30.2% in total hydrocarbons; Liquid phase contained H2O 63.7%, and the content of total hydrocarbons ()Ci) was 32.7%, methane content 13.6% occupied 41.6% in total hydrocarbons. According to the basin thermal evolution analysis, oil and gas formed boiling hydrocarbon inclusion because of structural cracks development which connected the upper atmosphere pressure reservoir and lower high-pressure source rock, it charged as burst-mode along cracks, boiling in the lower high-pressure space, captured by calcite veins. Boiling hydrocarbon inclusion provided evidence for oil and gas migration along cracks, and combined with the discover of crack high well in oil production plant, we thought that oil and gas migrated along crack in partical areas where it would discover high production crack well or form closed cracks reservoir.

1

Faculty of Agriculture, Kyushu University, Fukuoka 8128581, Japan (*correspondence: [email protected]) 2 Research Fellow of Japan Society for the Promotion of Science for Young Scientists (JSPS)

The genus Thermus are defined as aerobic, heterotrophic, non-motile, pigmented, non-spore-forming, and Gramnegative rods that can grow at temperatures over 70 °C. Previously, we isolated Thermus thermuohilus TMY from the geothermal power plant in Japan [1] and reported that strain TMY induces the precipitation of supersaturated silicic acid during exponeatial growth phase [2]. Notably, supersaturated silicic acid markedly stimulated expression of one cell envelope protein, which is named as silica-induced protein (Sip). The amino acid sequence of Sip showed significant similarity with the solute-binding protein of Fe3+ ABC transporters observed in other Thermus strains [3], however, little is known about the regulation of gene expression in response to supersaturated silicic acid. To determine the regulation of Sip expression, the transdriptional regulation mechanisms were investigated. Althogh sip operon comprises sip (solute-binding protein), permiase and ATPase, only sip gene was strongly transcribed in the silica-stressed condition. This might result from the fact that the palindromic structure located immidiately downstream of sip could function as the terminator of sip. Primer extension analysis revealed that transcription initiation site of sip is located at 34 bases upstream of start codon. -35 and -10 element of the sip promoter showed meaningful similarity to those of &A promoters commonly seen in T. thermophilus. Sip trnscription was enhanced by the addition of supersaturated silicic acid, however, sip was also transcribed in the irondeficient condition. Due to the negative charge of colloidal silica in silica-stressed condition, iron ions might be trapped by colloidal silica. Thermus cells might receive the signals of the existence of supersaturated silicic acid as the iron deficiency caused by colloidal silica. This mechanism of silica-responsible promoter could serve us more convenient and effective genetic tools for thermophile and must shed new light on bacterial biosilicification studies. [1] Fujino et al. (2008) J. Appl. Microbiol. 104, 70–78 [2] Inagaki et al. (1998) Biosci. Biotech. Biochem. 62, 1271– 1272 [3] Doi et al. (2009) Appl. Environ. Microbiol. 75, 2406– 2413

A310

Goldschmidt Conference Abstracts 2010

Prediction of iodine (I- and IO3-) adsorption and surface speciation on oxides by surface complexation modeling K. FUKUSHI1, T. NAGATA1 AND Y. TAKAHASHI2 1

Kanazawa University, Kakuma, Kanazawa, Ishikawa 9201192 Japan ([email protected]) 2 Hiroshima University, Higashi Hiroshima, Hiroshima 7398526 Japan

Aqueous iodine species occur mainly as iodide (I-) and iodate (IO3-), depending on the redox conditions. The adsorption of I- and IO3- on naturally occurring oxides is of environmental concern. The adsorption behaviors of I- and IO3- by iron and aluminum oxises were examined as a function of pH, ionic strength and solid concentration. The adsorption data were analyzed by means of an extended triple-layer model (ETLM) for surface complexation modeling to obtain the I- and IO3- adsorption reactions and these equilibrium constants. The adsorption of I- was determined to be an outer-sphere process from ETLM analysis, which was consistent with independent X-ray absorption near edge structure (XANES) observation of I- adsorbed on hydrous ferric oxide (HFO). The adsorption of IO3- was determined to be both an outer- and an inner-sphere process. The predicted model speciation of IO3on oxides showed that the inner-sphere species increase with increasing ionic strength and solid concentration while outersphere species distribute on wide range of pH conditions under low ionic strength. Additionally, the outer-sphere species are dominant for "-Al2O3, whereas the inner-sphere species are dominant for HFO and goethite. Comparison of adsorption equilibrium constants for iron and aluminum oxides based on site-occupancy standard states permitted prediction of I- and IO3- adsorption equilibrium constants for all oxides by means of the Born solvation theory. The batch adsorption data from previous reports for I- and IO3on oxides were reasonably reproduced by ETLM with the predicted equilibrium constants, confirming the validity of the present approach.

Interaction of Cu and Cd with organic matter and biogenic sulfide in periodically flooded soils B. FULDA1*, A. VOEGELIN2 AND R. KRETZSCHMAR1 1

Insitute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Switzerland (*correspondence: [email protected]) 2 Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland

The bioavailability and mobility of metal contaminants in periodically flooded soils such as freshwater floodplain soils or paddy soils may be of major concern with respect to ecosystem health, groundwater protection and food production. Reliable quantification of respective risks requires a sound mechanistic understanding of the processes controlling metal solubility at such sites, with special consideration of their periodic flooding and associated changes in soil redox-state and metal speciation. Based on our earlier observation that chalcophile metals may compete for biogenic sulfide in periodically flooded sulfate-limited soils [1], we performed laboratory incubation experiments with a soil adjusted to variable levels of Cu (2 and 5 mmol/kg), Cd (0.2 mmol/kg) and sulfate (sulfate balanced, limited and excess). X-ray absorption spectra of soil samples after different incubation times showed that Cd and Cu became increasingly S-coordinated during sulfate reduction. The sequestration of Cd into CdS was slightly enhanced in the presence of excess sulfate and slightly delayed under sulfate-limitation, confirming that competitive metal sulfide formation under sulfate-limitation affected metal dynamics. However, the observation that 45-60% of the Cu became S-coordinated prior to sulfate-reduction pointed to metal complexation by organic thiol-groups as another possible sequestration mechanism. 35-40% of Cd was found to be partially thiol-bound even in the oxic soil prior to flooding. Metal complexation with thiol-groups of soil organic matter (SOM) has previously been reported for Cd [2], but not for Cu. We assume that the fast reduction of the borderline cation Cu (II) to the chalcophile Cu (I) prior to sulfate-reduction induces a shift in organic Cu-complexation from carboxyland/or amine- to thiol-groups. Our results suggest that complexation of chalcophile metals with thiol-groups in SOM may interfere with their competition for biogenic sulfide in sulfate-limited soils. Further studies are required to quantify Cu (I)-thiol complexation by soil organic matter and its importance in periodically flooded soils. [1] Weber et al. (2009) GCA, 73, 5513–5527 [2] Karlsson et al. (2005) ES&T 39, 3048–3055

Goldschmidt Conference Abstracts 2010

A311

XAFS spectroscopy and molecular dynamics: Aqueous ions and ion pairs under non-ideal conditions

Petrological and tectonic evolution of the Palaeoarchean Barberton Greenstone Belt, South Africa

J.L. FULTON1, S.M. KATHMANN1, G.K. SCHENTER1, E.J. BYLASKA1, S.A. BOGATKO2 AND J.H. WEARE2

H. FURNES1*, M. DE WIT2 AND B. ROBINS3

1

Pacific Northwest National Laboratory, Richland, WA 99354 USA ([email protected]) 2 Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093

The combination of x-ray absorption fine structure (XAFS) spectroscopy with molecular dynamics (MD) simulation provides a powerful method to probe ion hydration and ion pairing in aqueous system including the extremely non-ideal conditions encountered in brines, acids and at high temperatures. XAFS probes the partial radial distribution of atoms about only the ion of interest. Further, the method can be used to resolve the fine details of first-shell structure by applying both photoelecton multiple scattering and multiple absorption-edge symmetry analyses [1]. An XAFS spectrum can be generated from an ensemble of molecular configurations that are the output from an MD simulation [2]. This MD-XAFS spectrum can then be directly compared to the experimental spectrum. The advantage of MD-XAFS is that all details of the local ion-water structure inherent in the simulations are captured in the MD-XAFS spectrum including first-shell coordination symmetry and any second solvation shell contributions. Classical intermolecular potentials used in MD simulations faithfully reproduce most of the aqueous structure of the alkali, alkaline earth and halide ions. An accurate description of transition metal cations and of contact ion pair structure is much more challenging problem. Ab initio-based molecular dynamics simulations have moved the quality of simulated structures to a new level. Using these methods we evalute the hydration struction of various metal cations including Ag+, Zn2+ and Ca2+. Further we discuss experimental results for structure of contact ion pairs for H3O+/Cl- and Ca2+/Cl-, Li+/Cl-, in brines, acids and at high temperatures. [1] Fulton, Kathmann, Schenter & Balasubramanian (2009) J. Phys. Chem. A, 113, 13976–13984. [2] Dang, Schenter, Glezakou & Fulton (2006) J. Phys. Chem. B 110, 23644.

1

Department of Earth Science & Centre for Geobiology, University of Bergen, Norway (*correspondence: [email protected]) 2 AEON and department of Geological Sciences, University of Cape Town, South Africa ([email protected]) 3 Department of Earth Science, University of Bergen, Norway ([email protected]) The Palaeoarchean Onverwacht Suite of the Barberton Greenstone Belt (BGB) comprises seven separate complexes of komatiite to dacitic volcanic and intrusive rocks, but with basalt as the predominant type. The complexes have tectonic contacts, are tectonically stacked with a total tectonostratigraphic thickness of ~15 km and have an age range of ~120 million years [1]. Some of the complexes have ophiolite-like lithological associations, whereas others are more akin to island-arc assemblages [1]. Detailed logging of the volcanic stratigraphy of the tectonostratigraphically upper Hooggenoeg (HC) and Kromberg Complexes (KC), show a dominance of non- to slightly-vesicular pillow lavas erupted beneath water 2000-4000 m deep [2]. The geochemical characteristics of the volcanic rocks of these two complexes show that the KC is composed entirely of low-MgO tholeiitic basalt, whereas the HC consists of tholeiitic to transitional basalt, as well as komatiitic lava. The basalts of the KC are depleted- to normal-MORB. Some of the HC lavas have boninitic affinities, and consistently elevated contents of Cs, Pb, Ba and Th in all the HC and KC lavas, give evidence of subduction. A compilation of all available geochemical data for mafic extrusive and intrusive rocks from the other complexes of the BGB show a large compositional spread. Elevated TiO2 at a given Al2O3 in komatiites from the Komati and Mendon Complexes, compared to the MgO-rich HC lavas, suggest that they may be generated from less-depleted sources. Two of the complexes are dominated by dacitic intrusives and subaerial extrusives. The juxtaposed complexes of the Onverwacht Suite were probably generated in subductioninfluenced oceanic spreading environments and island arcs. [1] de Wit et al. Precambian Research (submitted). [2] Furnes et al. Precambrian Research (submitted).

A312

Goldschmidt Conference Abstracts 2010

Aggregation of colloidal montmorillonite and organic matter: Implications for the estuarine processes

Chemical association of iron in individual atmospheric particles during Asian outflow season H. FURUTANI1*, J. JUNG1, K. MIURA2, A. TAKAMI3, S. KATO4, Y. KAJII4 AND M. UEMATSU1

YOKO FURUKAWA1* AND JANET WATKINS2 1

1

Naval Research Laboratory, Seafloor Sciences Branch, Stennis Space Center, Mississippi 39529, USA (*correspondence: [email protected]) 2 Naval Research laboratory, Seafloor Sciences Branch, Stennis Space Center, Mississippi 39529, USA Colloidal dispersion and aggregation in rivers and estuaries were investigated in a laboratory system containing a clay mineral (i.e. montmorillonite), organic matter (i.e. humic acid), and artificial estuarine water. The salinity of the artificial estuarine water was varied between 0 and 7.2 psu to mimic the estuarine mixing processes. The colloids and aggregates were characterized for their size distributions and zeta potential. The results indicate that the aggregation of colloidal suspensions that include humic acid does not follow the behavior predicted by the DLVO (Derjaguin and Landau, Verwey and Overbeek) theory, whereas the clay-only system follows the DLVO theory. For example, the DLVO theorybased calculations suggest the critical threashhold salinity of this system to be 0.4 psu. However, the experiments show it to be between 3.6 and 7.2 psu. The minimum net non-DLVO repulsive forces (i.e. primarily steric repulsion) for this system can be calculated by the surface interaction energy model that integrates the DLVO model calculations and experimental results. The magnitude of minimum steric repulsion is found to be in the same order as the van der Waals attraction. This study shows that salinity cannot be used to model the aggregation behavior of riverine colloidal suspensions in systems that contain humic acid. These findings agree the aggregation behaviors observed in the Pearl River (i.e. humic acid-rich river) and Mississippi River (i.e. humic acid-poor). In addition, the surface interaction energy model can be used to estimate the magnitudes of steric repulsion in other systems containing other types of organic matter.

Ocean Research Institute, University of Tokyo, Tokyo 1648639, Japan (*correspondence: [email protected]) 2 Tokyo University of Science, Tokyo 162-8601, JAPAN 3 National Institute for Environmental Studies, Ibaraki 3058506, Japan 4 Tokyo Metropolitan University, Tokyo 192-0397, JAPAN Using a single particle mass spectrometer (ATOFMS), size and chemical composition of ~2, 100, 000 individual atmospheric aerosol particles (D =100~1500 nm) were simultaneously observed on-line at the NIES Cape Hedo aerosol and atmospheric monitoring station in Okinawa Island, Japan (26.87°N, 128.26°E) during an Asian outflow season (March to April, 2008). On the basis of the mass spectrometric signature of Fe isotopic composition, Fe-containing aerosols were picked up and analyzed in detail. About 5~10% of observed aerosols was found to contain Fe, although the inclusion dropped to ~2% when oceanic air parcels (nonAsian outflow) arrived. The fraction of the Fe-containing aerosols was also size-dependent. Aerosols in the size range from 800~900 nm most frequently contained Fe (~15%). In addition to the dominant Fe-rich type, Fe found to be present in several aerosol chemical types. Potassium, Na, Al, organic carbon (OC), and sulfate were almost always associated with Fe. Phosphorus, Si, Li, Pb, and elemental carbon (EC) were also frequently associated with Fe, although different aerosol types had different amount of these elements and compounds, suggesting existence of multiple sources and/or atmospheric processes for the Fe-containing aerosols. Association of nitrate increased in large aerosols (D > 700 nm). The frequent association of Li implied strong influence of coal combustion aerosol sources on the Fe composition. A V-rich type exhibited quite different chemical association. The type contained Al, OC, EC and sulfate, but none of K, Na, P, Si, Li, and Pb. The unique assocation of the V-rich type suggested that combustion of low-grade fuel was also a source of Fecontaining aerosols. Further detailed chemical association during the Asian outflow will be disccused and compared with those over the North and South Pacific oceans observed using the same analytical technique.