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Vibrational spectroscopic characterization of growth bands in Porites coral from South China Sea
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 112 (2013) 95–100
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Vibrational spectroscopic characterization of growth bands in Porites coral from South China Sea Yinxian Song a,b,c,⇑, Kefu Yu a,c, Godwin A. Ayoko b, Ray L. Frost b, Qi Shi a, Yuexing Feng c, Jianxin Zhao c a Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Xingang West Road 164, Guangzhou 510301, Guangdong Province, PR China b Discipline of Nanotechnology and Molecular Science, School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, GPO Box 2324, Brisbane, Queensland 4001, Australia c Radiogenic Isotope Facility, School of Earth Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
We have studied the Raman spectra
in different growth bands of Porites coral. Raman spectra show vaterite could be the precursor of coral aragonitic skeleton. The positional shift in the infrared spectra correlate significantly to minor elements.
a r t i c l e
i n f o
Article history: Received 7 November 2012 Received in revised form 2 April 2013 Accepted 10 April 2013 Available online 19 April 2013 Keywords: Raman Infrared reflectance spectroscopy Porites coral
a b s t r a c t A series of samples from different growth bands of Porites coral skeleton were studied using Raman, infrared reflectance methods. The Raman spectra proved that skeleton samples from different growth bands have the same mineral phase as aragonite, but a band at 133 cm 1 for the top layer shows a transition from 120 cm 1 for vaterite to 141 cm 1 for aragonite. It is inferred that the vaterite should be the precursor of aragonite of coral skeleton. The positional shift in the infrared spectra of the skeleton samples from growth bands correlate significantly to their minor elements (Li, Mg, Sr, Mn, Fe and U) contents. Mg, Sr and U especially have significant negative correlations with the positions of the antisymmetric stretching band m3 at 1469 cm 1. And Li shows a high negative correlation with m2 band (855 cm 1), while Sr and Mn show similar negative correlation with m4 band (712 cm 1). And Mn also shows a negative correlation with m1 band (1082 cm 1). A significantly negative correlation is observed for U with m1 + m4 band (1786 cm 1). However, Fe shows positive correlation with m1, m2, m3, m4 and m1 + m4 bands shifts, especially a significant correlation with m1 band (1082 cm 1). New insights into the characteristics of coral at different growth bands of skeleton are given in present work. Ó 2013 Elsevier B.V. All rights reserved.
Introduction
⇑ Corresponding author at: Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Xingang West Road 164, Guangzhou 510301, Guangdong Province, PR China. Tel.: +61 7 3346 9752. E-mail address: [email protected] (Y. Song). 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.04.049
Coral reefs are mainly distributed in tropic and subtropic oceans, such as those in the Mediterranean, Caribbean, Australian and Southeast Asian areas [1]. As the main calcium carbonate source around the world, coral reefs contribute 7–15% of global CaCO3 to the reduction of greenhouse gases, annually [2]. Coral
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reefs consist of various coral deposits, among which Porites is one of main genera involved in the formation of coral reefs [3]. The skeleton of natural coral (Porites) consists mainly of calcium carbonate in the form of aragonite which can be doped with other cations such as Mg, Sr, Ba, U and the organic matrix [4–6]. As is well known, coral skeleton is composed of biogenic aragonite/calcite which forms a layered structure. The polyp generates the carbonate skeleton with annual banding, and lives on the surface of the skeleton [7]. The deposition characteristics of coral carbonates accumulating in the skeleton make the coral function as a chronometer [8,9], in the same way as tree rings and speleothems (including stalagmite, flowstone, etc.). The formation of biogenic aragonite layer is impacted mainly by sea temperatures and the ocean environment [10], which is the reason that Porites coral can become a recorder of changes of climate and environment. Fundamentally, coral reefs function as a measure of climate change. There is a long history of research of mineral phases in the marine environment, especially for coral carbonates [10–12], and the spectral characteristics of coral have been analyzed using FT-Raman and Fourier transform infrared spectroscopy (FTIR) [13–15]. Because minor elements such as Mg, Sr, Mn and U are incorporated into calcium carbonate from seawater during formation and mineralization of biogenic CaCO3, changes in the composition of calcium carbonate will lead in changes in the spectra. For example, Bischoff et al. and Edwards et al. showed that positional disorder of carbonate ions using Raman spectroscopy for biogenic Mg-calcite is greater than for synthetic Mg-calcite [16,17]. However, the m2 and m4 band positions in the infrared spectra for different biogenic aragonite and calcite shift linearly with the concentration of Mg2+ and Sr2+ incorporated into these carbonates [13,18]. A recent study using Raman spectroscopy of biological vaterite as a precursor of aragonite [19] provides a better understanding of the formation process of biogenic aragonite by comparing the Raman spectra of vaterite and aragonite [20]. Although some work on the spectroscopy of marine biogenic carbonate have been undertaken previously [14,15,20,21], studies on the vibrational spectroscopy and characteristics of mineral phases from coral skeleton growth bands which function as chronometer are rarely reported. Therefore the current study investigates the Raman and infrared spectroscopy of minerals from different coral skeleton growth bands. And the positional shift of infrared spectra for different growth bands is studied by analyzing the correlation between the position of infrared spectra and minor elements (Li, Mg, Sr, Mn, Fe and U) of different growth bands in coral. Changes in the components of coral growth bands will be discussed.
Fig. 1. X-radiography of skeletal slabs of coral (Porites) collected from the South China Sea. Location and year represented by growth band of samples collection are indicated.
Experimental Coral sample Living Porites coral (named as XL1) was collected, from Xiaodonghai, Hainan Island. The coral samples were washed with freshwater then sectioned by water-lubricated diamond-bit masonry saw in order to obtain a set of parallel slabs that are 8 mm thick. Dry coral slab was X-radiographed to show the annual growth bands (Fig. 1). The coral slabs were soaked and sterilized by 10% H2O2 for 48 h, and cleaned 3 times in an ultrasonic bath using Milli-Q water, and then air-dried in the oven at 60 °C for 48 h. The selected coral skeleton samples were cut off using ceramic knife on the growth bands shown in the X-radiography and then ground to powder for measurement. Annual-resolution sub-samples were sliced continuously using a ceramic knife along the
Fig. 2. Raman spectra of coral samples in the 100–1500 cm aragonite for coral skeleton samples.
1
region showing
growth bands of coral slabs and then ground to powder for measurement. A clear pattern of alternating bands of high and low density is visible in Fig. 2. Dating was accomplished by
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counting these annual bands [8]. The growth bands from which samples were selected represented different coral ages, for the years 2006, 2002, 1997, 1987, 1957, 1930, 1905 and 1880, the samples were named as XL1-1, XL1-5, XL1-10, XL1-20, XL1-50, XL1-75, XL1-100 and XL1-125 respectively (Fig. 1). Chemical analysis The chemical composition of coral samples were measured at the Radiogenic Isotope Facility (RIF), at the Centre for Microscopy & Microanalysis (CMM) of Queensland University. Small quantities (3 mg) of coral samples were dissolved in 6 ppb spiked 2 wt.% HNO3. Li, Sr, Mg, Mn, Fe and U were measured using Thermo ICPMS X SERIES II (Thermo Fisher Scientific, America) ICP-MS (Inductively Coupled Plasma-Mass Spectrometry). Analyzed data were assessed for accuracy and precision using quality assurance and quality control (QA/QC) program which included reagent blanks and certified geochemical reference materials (W-2, JCp-1 and BIR-1) with deviation less than 5%. Raman spectroscopy All spectroscopic experiments were undertaken at the Queensland University of Technology (QUT). Powdered coral skeleton samples were placed on a polished metal surface on the stage of an Olympus BHSM microscope, equipped with 10, 20, and 50 objectives. The microscope is part of a Renishaw 1000 Raman microscope system, which also includes a monochromator, a filter system and a CCD detector (1024 pixels). The Raman spectra were excited by a Spectra-Physics model 127 He–Ne laser producing highly polarized light at 633 nm and collected at a nominal resolution of 2 cm 1 and a precision of ±1 cm 1 in the range between 100 and 4000 cm 1. Repeated acquisitions on the crystals using the highest magnification (50) were accumulated to improve the signal to noise ratio of the spectra. Spectra were calibrated using the 520.5 cm 1 line of a silicon wafer. Infrared reflectance spectroscopy As a quick and non-destructive method, infrared reflectance spectra for coral samples were obtained using a Nicolet Nexus 870 FTIR spectrometer with a smart endurance single bounce diamond ATR cell. Spectra over the 4000–525 cm 1 range were obtained by the co-addition of 128 scans with a resolution of 4 cm 1 and a mirror velocity of 0.6329 cm/s. Spectra were coadded to improve the signal to noise ratio. Spectral manipulation such as baseline correction/adjustment and smoothing were performed using the Spectracalc software package GRAMS (Galactic Industries Corporation, NH, USA). Band component analysis was undertaken using the Jandel ‘‘Peakfit’’ software package that enabled the type of fitting function to be selected and allows specific parameters to be fixed or varied accordingly. Band fitting was done using a Lorentzian–Gaussian cross-product function with the minimum number of component bands used for the fitting process. The Lorentzian–Gaussian ratio was maintained at values greater than 0.7 and fitting was undertaken until reproducible results were obtained with squared zcorrelations of r2 greater than 0.99. Results and discussion Minor elements in coral Some selected minor elements in the coral samples, including Li, Mg, Sr, Mn, Fe and U were measured using ICP-MS. These results
Table 1 Concentrations (lg/g) of minor elements selected in the coral growth bands. Sample
Year
Li
Mg
Sr
Mn
Fe
U
XL1-1 XL1-5 XL1-10 XL1-20 XL1-50 XL1-75 XL1-100 XL1-125
2006 2002 1997 1987 1957 1930 1905 1880
0.53 0.42 0.48 0.40 0.52 0.43 0.43 0.47
1175.58 965.82 1017.86 1123.72 1096.67 982.39 877.02 983.67
7865.02 7508.51 7801.90 7452.31 7899.42 6813.50 6675.36 6679.04
1.61 0.76 0.64 0.74 0.84 0.52 0.29 0.58
1280.60 1277.96 1335.07 1342.27 1431.62 1301.72 1296.06 1616.43
2.21 2.87 2.86 2.58 2.76 2.42 2.37 2.37
proved that the Porites coral sample XL1 from South China Sea has high Mg (>800 lg/g) and Sr (>6500 lg/g) concentration (Table 1), which are the most thoroughly studied elements in some benthonic mollusc shells and Cnidarian and skeletal marine minerals [13,15,22,23]. As described earlier, different minor elements such as Sr and Mg, occur in the aragonite skeletons and shells. For example, aragonitic layers with low Sr (<2000 lg/g) and low Mg (<600 lg/g) occur in Bivalvia and Gastropoda [23]; P.venus seashells have low Sr (2000 lg/g) and Mg (200 lg/g) [15]; low Sr (2000 lg/g) and Mg (400 lg/g) contents are also present in Mollusca while high Sr (>6500 lg/g) and Mg (>1500 lg/g) occur in Cnidaria [13]. In the current study, Porites coral samples XL1 has relatively lower Sr and Mg, but higher Fe content than the sample from Malaysia (Table 1) [15]. The concentration of Fe exceeds 1000 lg/g, which is higher than Mg in XL. And the contents of Li, Mn and U are below 3 lg/g (Table 1). Although U content falls into the range reported by previous research [24–26], Mn in XL1 is lower than those in some studies [27–29]. Changes in the contents of these elements at different growth bands could lead to some infrared spectroscopic bands shifts, such as those observed for Sr and Mg [13,18].
Raman spectroscopy The Raman spectroscopy of coral skeleton samples in the 1500– 100 cm 1 spectral range is shown in Fig. 2. The spectra of samples are similar, and consist of a series of sharp peaks, most of which are assigned to the symmetric stretching mode (m1) at 1083 cm 1, inplane bending mode (m4) at 701 and 705 cm 1, and lattice modes at 205 cm 1 and 151 cm 1, which define the peaks of aragonite as described in earlier research [15,17,20,21,30]. In the present work, a very weak Raman band around 1462 cm 1 of aragonite was attributed to the m3 antisymmetric stretching vibrational mode. Therefore, Raman spectra showed that the mineral phase of samples from growth bands is aragonite. As illustrated in Fig. 2, samples from different growth bands of coral skeletons have the same mineral phase. But in the 300– 100 cm 1 region, sample XL1-1 shows some different peaks when compared with the other spectra (Fig. 3). For example, a peak at 132.9 cm 1 was present in the spectrum of XL1-1, but for the other samples this peak shifted to 141 cm 1; and the peak at 178.6 cm 1 for XL1-1 was split into two bands at 179 and 189 cm 1. Raman studies show that another metastable calcium carbonate mineral, vaterite, has a series of peaks attributed to lattice vibrations at 106, 120, 151, 175, 210, 268 and 302 cm 1 [20,31]. Although some studies about the precursors of biogenic carbonate showed that amorphous phase or vaterite occurred as potential precursors [32,33], the peaks for XL1-1 showed a possibility that the aragonitic mineral phase of the skeleton coral was transformed from vaterite. For example, as shown in Fig. 3, the peak at 133 cm 1 in XL1-1 showed a transition phase indicating which peak of vaterite at 120 cm 1 shifts to peak at 141 cm 1 of aragonite. Similarly, the peak at 178 cm 1 in XL1-1 showed a
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transition that indicated that the 175 cm 1 band of vaterite shifted to 179 cm 1 for aragonite. In an earlier research work [17], Huntite showed similar Raman peaks at 118 cm 1, 155 cm 1 and 272 cm 1 to vaterite. But Huntite is Mg-rich carbonate. So we can infer that the Raman shift at the bands between 300 cm 1 and 100 cm 1 seems to arise from lattice change of mineral. And for all Raman spectra of growth bands, a broad weak band at 267 cm 1 seems to show that the band at 268 cm 1 for vaterite weakened to 261 cm 1 for aragonite. Although some previous studies did not come to a firmconclusion about the precursor of biogenic carbonate, lots of reports about the transition of vaterite to aragonite are available in the literature [19,34–36]. In the present work, it is proposed that the vaterite could be the precursor of aragonite phase of coral skeleton from South China Sea. Infrared reflectance spectroscopy and structure composition
Fig. 3. Raman spectra of coral samples in the 100–300 cm 1 region showing the peak at 133 cm 1 for XL 1-1 shifts to peak at 141 cm 1 for other samples.
The infrared reflectance spectra from the growth bands of coral in 600–4000 cm 1 region are reported in Fig. 4. As shown in the Raman spectra, all samples for the different growth bands display the aragonite phase. For the sample in the first layer of the skeleton, the peaks in the 3000–3600 cm 1region, and 2923 cm 1, 2854 cm 1 were attributed to water and organic matter as shown in the spectrum of XL1-1. In the 600–2000 cm 1 region, all spectra clearly showed bands due to aragonite mainly. The intense bands at 1469, 855 cm 1 and the doublet at 712 and 699 cm 1 are assigned to the antisymmetric stretching mode m3, out-of-plane bending mode m2 and in-plane bending mode m4 of CO23 . Symmetric stretching mode m1 occurs at 1082 cm 1 as a low intensity peak, and a combined m1 + m4 mode presents at around 1786 cm 1 as a very weak band described in earlier studies [15]. Otherwise, two low intensity bands at 1665 and 1030 cm 1 in the spectrum of XL1-1 could be assigned to amide [13,18] and (Si)–OH [37], which resulted from the signal of the organic matter and the incorporated impurities; these (Si)–OH impurities could come from eroded soil and marine sediments. As it can be seen in Fig. 4, the positions of stretching and bending modes, such as m1, m2 m3 and m4, change with samples from dif-
Fig. 4. Infrared reflectance spectra of coral samples in the 4000–600 cm
1
region.
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Y. Song et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 112 (2013) 95–100 Table 2 Correlation of minor elements and main infrared spectra peaks of the different growth bands. Li 1
m4 (712 cm ) m2 (855 cm 1) m1 (1082 cm 1) m3 (1469 cm 1) m1 + m4 (1786 cm 1) a b
0.465 0.663 0.384 0.378 0.072
Mg 0.227 0.064 0.288 0.498 0.117
Sr
Mn
0.662 0.458 0.463 0.934a 0.636
0.591 0.441 0.627 0.465 0.016
Fe 0.553 0.410 0.749b 0.486 0.292
U 0.26 0.062 0.145 0.639 0.937a
Correlation is significant at the 0.01 level (2-tailed). Correlation is significant at the 0.05 level (2-tailed).
ferent growth bands of the aragonitic skeleton. According to Böttcher et al., in natural inorganic or organic Mg calcite, Mg2+ content has a linear correlation with the position of m4 band of Mg calcite as observed at 711 cm 1 [17,38]. Some previous research also studied the cation substitution in carbonate system, like Calcite– Magnesite–siderite–rhodochrosite [39–41] and CdCO3 [42]. Positive correlation between Sr2+, Mg2+ content and m4 position of biogenic calcite was also studied by Dauphin [18]. In Dauphin’s other work [13], Sr2+, Mg2+ in aragonitic skeletons of marine geological materials showed negative correlation with m2 band between 856–866 cm 1. But in Raman spectroscopic investigation of carbonates system [43], Mg contents of different carbonates showed a positive correlation in Raman shifts for m1, m2, m3 and m4 bands. In the current work, it is shown that with the exception of Fe, some minor elements including Li, Mg, Sr, Mn and U have negative correlation with the main peaks in infrared spectra of samples (Table 2). In comparison with earlier research, Mg does not show significant correlation with the m2 band. Besides the shift of m2 and m4 bands, the minor elements have significant correlation with m3 and m1 bands. As shown in Table 2, Li shows a high negative correlation with m2 band (855 cm 1) (r = 0.663), while Sr and Mn show similar negative correlation with m4 band (712 cm 1) (r = 0.662 and r = 0.591 respectively). Mn also shows a negative correlation with m1 band (1082 cm 1) (r = 0.627). But in comparison with other research work [39], Mn concentration in carbonate system showed positive correlation with m4 band and negative correlation with m2 band in infrared spectroscopy, respectively. Mg and U are negatively correlated with m3 band (1469 cm 1) (r = 0.498 and r = 0.639) as Sr (r = 0.934), which is different from the results obtained in previous research work [13,18]. For U, a significantly negative correlation with m1 + m4 band (1786 cm 1) is observed (r = 0.937). It is shown that Fe is an exception in that it has positive correlation with m1, m2, m3, m4 and m1 + m4 bands, and a significant correlation with m1 band (1082 cm 1) (r = 0.749). A similar phenomenon occurred in siderite–magnesite system [40], in which Fe content is correlated positively with m2, but negatively with m3 and m4. With respect to the Raman spectra of carbonates [43], the Fe content in carbonates also showed positive correlation with m3 and m4 Raman shifts. Although different results are observed, the correlation of the composition of minor elements with bands shift in infrared of aragonitic skeleton samples of coral demands further study. Meanwhile prediction models of Sr, Mg and U in coral growth bands could be constructed through bands shifts in infrared spectroscopy, which will be a quick method to build a model for understanding climate change and reconstruction of paleoclimate [44–46]. Conclusions Characteristics of carbonate samples from different growth bands of Porites coral skeletons were studied by Raman spectroscopy, infrared reflectance spectroscopy and infrared emission spectroscopy. Raman spectra for samples showed that coral skeleton consists of aragonite, but the ‘‘youngest’’ samples XL1-1 shows
a probable transition phase of vaterite to aragonite, which provides evidence that vaterite is a precursor of skeletal aragonite of Porites coral. Shifts in the main bands, including m3 (1469 cm 1), m1 (1082 cm 1), m2 (855 cm 1) and m4 (712 cm 1) bands in infrared spectra for skeleton samples indicate that the variation of minor elements contents in different growth bands could influence the characteristic positions of CO23 in the infrared spectra. In particular, Mg, Sr and U have significant correlation with the positional shift of the antisymmetric stretching band m3 (1469 cm 1). Li shows a high negative correlation with m2 band (855 cm 1) and Mn shows a negative correlation with m1 band (1082 cm 1). A significantly negative correlation is observed for U with m1 + m4 band (1786 cm 1). As an exception, Fe has a positive correlation with m1, m2, m3, m4 and m1 + m4 bands shifts, especially a significant correlation with m1 band (1082 cm 1). Acknowledgements This work was funded by the National Key Basic Research Program of China (Nos. 2013CB956102 and 2010CB950101), the ‘‘Strategic Priority Research Program’’ of the Chinese Academy of Sciences (Grant No. XDA05080301), the National Natural Science Foundation of China (Nos. 40830852, 41025007 and 41203074), and an Australian Research Councile discovery project (DP0773081). And Queensland University of Technology, School of Chemistry, Physics and Mechanical Engineering and the University of Queensland, Radiogenic Isotope Facility (RIF) lab of Centre for Microscopy and Microanalysis (CMM) supply technical support. The assistance of Yunfei Xi and Haibo Liu at Queensland University of Technology, is gratefully acknowledged.
References [1] M.M. Scott, Young Oxford Book of Ecology, Oxford University Press, Oxford, UK, 1994. [2] A. Suzuki, H. Kawahata, in: M. Shiyomi, H. Kawahata, H. Koizumi, A. Tsuda, Y. Awaya (Eds.), Global Environmental Change in the Ocean and on Land, Terrapub, Tokyo, 2004, pp. 229–248. [3] L. Nothdurft, G. Webb, Facies 53 (2007) 1–26. [4] S.A. Wainwright, Exp. Cell Res. 34 (1964) 213–230. [5] J.H. Vandermeulen, N. Watabe, Mar. Biol. 23 (1973) 47–57. [6] G. Guillemin, J.L. Patat, J. Fournie, M. Chetail, J. Biomed. Mater. Res. 21 (1987) 557–567. [7] J.M. Lough, D.J. Barnes, J. Exp. Mar. Biol. Ecol. 135 (1990) 35–57. [8] D.W. Knutson, R.W. Buddemeier, S.V. Smith, Science 177 (1972) 270. [9] T.P. Scoffin, A.W. Tudhope, B.E. Brown, H. Chansang, R.F. Cheeney, Coral Reefs 11 (1992) 1–11. [10] M.W. Miller, Mar. Ecol. Prog. Ser. 122 (1995) 217–225. [11] T.F. Goreau, Biol. Bull. 116 (1959) 59–75. [12] C. Langdon, T. Takahashi, C. Sweeney, D. Chipman, J. Goddard, F. Marubini, H. Aceves, H. Barnett, M.J. Atkinson, Global Biogeochem. Cycles 14 (2000) 639– 654. [13] Y. Dauphin, Appl. Spectrosc. 51 (1997) 253–258. [14] B. Kaczorowska, A. Hacura, T. Kupka, R. Wrzalik, E. Talik, G. Pasterny, A. Matuszewska, Anal. Bioanal. Chem. 377 (2003) 1032–1037. [15] F.Z. Zakaria, J. Mihály, I. Sajó, R. Katona, L. Hajba, F.A. Aziz, J. Mink, J. Raman Spectrosc. 39 (2008) 1204–1209. [16] W.D. Bischoff, S.K. Sharma, F.T. Mackenzie, Am. Mineral. 70 (1985) 581–589.
100
Y. Song et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 112 (2013) 95–100
[17] H.G.M. Edwards, S.E.J. Villar, J. Jehlicka, T. Munshi, Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 61 (2005) 2273–2280. [18] Y. Dauphin, Appl. Spectrosc. 53 (1999) 184–190. [19] B. Hasse, H. Ehrenberg, J.C. Marxen, W. Becker, M. Epple, Chem. A European J. 6 (2000) 3679–3685. [20] U. Wehrmeister, A.L. Soldati, D.E. Jacob, T. Häger, W. Hofmeister, J. Raman Spectrosc. 41 (2010) 193–201. [21] J. Urmos, S.K. Sharma, F.T. Mackenzie, Am. Mineral. 76 (1991) 641–646. [22] H.W. van der Marel, Atlas of Infrared Spectroscopy of Clay Minerals and Their Admixtures, Elsevier Scientific Publication, Co., Amsterdam, 1976. [23] Y. Dauphin, A. Denis, Compar. Biochem.Phys. – Part A: Molec. amp Integr. Phys. 126 (2000) 367–377. [24] G. Thompson, H.D. Livingston, Earth Planet. Sci. Lett. 8 (1970) 439–442. [25] P.K. Swart, J.A.E.B. Hubbard, Coral Reefs 1 (1982) 13–19. [26] G. Wei, M. Sun, X. Li, B. Nie, Palaeogeogr., Palaeocl., Palaeogeogr. 162 (2000) 59–74. [27] Z. Peng, J. Liu, C. Zhou, B. Nie, T. Chen, Chin. J. Geochem. 25 (2006) 132–138. [28] S.A. Al-Rousan, R.N. Al-Shloul, F.A. Al-Horani, A.H. Abu-Hilal, Mar. Pollut. Bull. 54 (2007) 1912–1922. [29] N. Jayaraju, B.C.S.R. Reddy, K. Reddy, Soil Sediment Contam. 18 (2009) 445– 454. [30] V.C. Farmer, The Infrared Spectra Of Minerals Mineralogical Society Monograph, Mineralogical Society London, 1974. [31] R.W. Gauldie, S.K. Sharma, E. Volk, Comp. Biochem. Physiol. A Physiol. 118 (1997) 753–757.
[32] S. Weiner, J. Mahamid, Y. Politi, Y. Ma, L. Addadi, Front. Mater. Sci. China 3 (2009) 104–108. [33] P.L. Clode, K. Lema, M. Saunders, S. Weiner, Coral Reefs 30 (2011) 1–8. [34] Q. Shen, L. Wang, Y. Huang, J. Sun, H. Wang, Y. Zhou, D. Wang, J. Phys. Chem. B 110 (2006) 23148–23153. [35] W. Bao, H. Li, Y. Zhang, Cryst. Res. Technol. 44 (2009) 395–401. [36] A. Sarkar, S. Mahapatra, Cryst. Growth Des. 10 (2010) 2129–2135. [37] N. Kovacˇ, J. Gaganeli, O. Bajt, B. Orel, A. Šurca Vuk, RMZ-Mater Geoenviron. 52 (2005) 81–85. [38] M.E. Böttcher, P.-L. Gehlken, D.F. Steele, Solid State Ionics 101–103 (2) (1997) 1379–1385. [39] M.E. Böttcher, P.L. Gehlken, E. Usdowski, Contr. Mineral. Petrol. 109 (1992) 304–306. [40] J.V. Dubrawski, A.L. Channon, S.S.J. Warne, Am. Mineral. 74 (1989) 187–190. [41] M.E. Böttcher, P.-L. Gehlken, Neues Jahrb. Mineral. Abh. 169 (1995) 81–95. [42] M.E. Böttcher, P.-L. Gehlken, Appl. Spectrosc. 51 (1997) 130–131. [43] N. Rividi, M. van Zuilen, P. Philippot, B. Menez, G. Godard, E. Poidatz, Astrobiology 10 (2010) 293–309. [44] J.W. Beck, R.L. Edwards, E. Ito, F.W. Taylor, J. Recy, F. Rougerie, P. Joannot, C. Henin, Science 257 (1992) 644–647. [45] T. Mitsuguchi, E. Matsumoto, O. Abe, T. Uchida, P.J. Isdale, Science 274 (1996) 961–963. [46] K.-F. Yu, J.-X. Zhao, G.-J. Wei, X.-R. Cheng, T.-G. Chen, T. Felis, P.-X. Wang, T.-S. Liu, Palaeogeogr., Palaeoclimatol., Palaeoecol. 218 (2005) 57–73.
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Vibrational spectroscopic characterization of growth bands in Porites coral from South China Sea Yinxian Song a,b,c,⇑, Kefu Yu a,c, Godwin A. Ayoko b, Ray L. Frost b, Qi Shi a, Yuexing Feng c, Jianxin Zhao c a Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Xingang West Road 164, Guangzhou 510301, Guangdong Province, PR China b Discipline of Nanotechnology and Molecular Science, School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, GPO Box 2324, Brisbane, Queensland 4001, Australia c Radiogenic Isotope Facility, School of Earth Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
We have studied the Raman spectra
in different growth bands of Porites coral. Raman spectra show vaterite could be the precursor of coral aragonitic skeleton. The positional shift in the infrared spectra correlate significantly to minor elements.
a r t i c l e
i n f o
Article history: Received 7 November 2012 Received in revised form 2 April 2013 Accepted 10 April 2013 Available online 19 April 2013 Keywords: Raman Infrared reflectance spectroscopy Porites coral
a b s t r a c t A series of samples from different growth bands of Porites coral skeleton were studied using Raman, infrared reflectance methods. The Raman spectra proved that skeleton samples from different growth bands have the same mineral phase as aragonite, but a band at 133 cm 1 for the top layer shows a transition from 120 cm 1 for vaterite to 141 cm 1 for aragonite. It is inferred that the vaterite should be the precursor of aragonite of coral skeleton. The positional shift in the infrared spectra of the skeleton samples from growth bands correlate significantly to their minor elements (Li, Mg, Sr, Mn, Fe and U) contents. Mg, Sr and U especially have significant negative correlations with the positions of the antisymmetric stretching band m3 at 1469 cm 1. And Li shows a high negative correlation with m2 band (855 cm 1), while Sr and Mn show similar negative correlation with m4 band (712 cm 1). And Mn also shows a negative correlation with m1 band (1082 cm 1). A significantly negative correlation is observed for U with m1 + m4 band (1786 cm 1). However, Fe shows positive correlation with m1, m2, m3, m4 and m1 + m4 bands shifts, especially a significant correlation with m1 band (1082 cm 1). New insights into the characteristics of coral at different growth bands of skeleton are given in present work. Ó 2013 Elsevier B.V. All rights reserved.
Introduction
⇑ Corresponding author at: Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Xingang West Road 164, Guangzhou 510301, Guangdong Province, PR China. Tel.: +61 7 3346 9752. E-mail address: [email protected] (Y. Song). 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.04.049
Coral reefs are mainly distributed in tropic and subtropic oceans, such as those in the Mediterranean, Caribbean, Australian and Southeast Asian areas [1]. As the main calcium carbonate source around the world, coral reefs contribute 7–15% of global CaCO3 to the reduction of greenhouse gases, annually [2]. Coral
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reefs consist of various coral deposits, among which Porites is one of main genera involved in the formation of coral reefs [3]. The skeleton of natural coral (Porites) consists mainly of calcium carbonate in the form of aragonite which can be doped with other cations such as Mg, Sr, Ba, U and the organic matrix [4–6]. As is well known, coral skeleton is composed of biogenic aragonite/calcite which forms a layered structure. The polyp generates the carbonate skeleton with annual banding, and lives on the surface of the skeleton [7]. The deposition characteristics of coral carbonates accumulating in the skeleton make the coral function as a chronometer [8,9], in the same way as tree rings and speleothems (including stalagmite, flowstone, etc.). The formation of biogenic aragonite layer is impacted mainly by sea temperatures and the ocean environment [10], which is the reason that Porites coral can become a recorder of changes of climate and environment. Fundamentally, coral reefs function as a measure of climate change. There is a long history of research of mineral phases in the marine environment, especially for coral carbonates [10–12], and the spectral characteristics of coral have been analyzed using FT-Raman and Fourier transform infrared spectroscopy (FTIR) [13–15]. Because minor elements such as Mg, Sr, Mn and U are incorporated into calcium carbonate from seawater during formation and mineralization of biogenic CaCO3, changes in the composition of calcium carbonate will lead in changes in the spectra. For example, Bischoff et al. and Edwards et al. showed that positional disorder of carbonate ions using Raman spectroscopy for biogenic Mg-calcite is greater than for synthetic Mg-calcite [16,17]. However, the m2 and m4 band positions in the infrared spectra for different biogenic aragonite and calcite shift linearly with the concentration of Mg2+ and Sr2+ incorporated into these carbonates [13,18]. A recent study using Raman spectroscopy of biological vaterite as a precursor of aragonite [19] provides a better understanding of the formation process of biogenic aragonite by comparing the Raman spectra of vaterite and aragonite [20]. Although some work on the spectroscopy of marine biogenic carbonate have been undertaken previously [14,15,20,21], studies on the vibrational spectroscopy and characteristics of mineral phases from coral skeleton growth bands which function as chronometer are rarely reported. Therefore the current study investigates the Raman and infrared spectroscopy of minerals from different coral skeleton growth bands. And the positional shift of infrared spectra for different growth bands is studied by analyzing the correlation between the position of infrared spectra and minor elements (Li, Mg, Sr, Mn, Fe and U) of different growth bands in coral. Changes in the components of coral growth bands will be discussed.
Fig. 1. X-radiography of skeletal slabs of coral (Porites) collected from the South China Sea. Location and year represented by growth band of samples collection are indicated.
Experimental Coral sample Living Porites coral (named as XL1) was collected, from Xiaodonghai, Hainan Island. The coral samples were washed with freshwater then sectioned by water-lubricated diamond-bit masonry saw in order to obtain a set of parallel slabs that are 8 mm thick. Dry coral slab was X-radiographed to show the annual growth bands (Fig. 1). The coral slabs were soaked and sterilized by 10% H2O2 for 48 h, and cleaned 3 times in an ultrasonic bath using Milli-Q water, and then air-dried in the oven at 60 °C for 48 h. The selected coral skeleton samples were cut off using ceramic knife on the growth bands shown in the X-radiography and then ground to powder for measurement. Annual-resolution sub-samples were sliced continuously using a ceramic knife along the
Fig. 2. Raman spectra of coral samples in the 100–1500 cm aragonite for coral skeleton samples.
1
region showing
growth bands of coral slabs and then ground to powder for measurement. A clear pattern of alternating bands of high and low density is visible in Fig. 2. Dating was accomplished by
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counting these annual bands [8]. The growth bands from which samples were selected represented different coral ages, for the years 2006, 2002, 1997, 1987, 1957, 1930, 1905 and 1880, the samples were named as XL1-1, XL1-5, XL1-10, XL1-20, XL1-50, XL1-75, XL1-100 and XL1-125 respectively (Fig. 1). Chemical analysis The chemical composition of coral samples were measured at the Radiogenic Isotope Facility (RIF), at the Centre for Microscopy & Microanalysis (CMM) of Queensland University. Small quantities (3 mg) of coral samples were dissolved in 6 ppb spiked 2 wt.% HNO3. Li, Sr, Mg, Mn, Fe and U were measured using Thermo ICPMS X SERIES II (Thermo Fisher Scientific, America) ICP-MS (Inductively Coupled Plasma-Mass Spectrometry). Analyzed data were assessed for accuracy and precision using quality assurance and quality control (QA/QC) program which included reagent blanks and certified geochemical reference materials (W-2, JCp-1 and BIR-1) with deviation less than 5%. Raman spectroscopy All spectroscopic experiments were undertaken at the Queensland University of Technology (QUT). Powdered coral skeleton samples were placed on a polished metal surface on the stage of an Olympus BHSM microscope, equipped with 10, 20, and 50 objectives. The microscope is part of a Renishaw 1000 Raman microscope system, which also includes a monochromator, a filter system and a CCD detector (1024 pixels). The Raman spectra were excited by a Spectra-Physics model 127 He–Ne laser producing highly polarized light at 633 nm and collected at a nominal resolution of 2 cm 1 and a precision of ±1 cm 1 in the range between 100 and 4000 cm 1. Repeated acquisitions on the crystals using the highest magnification (50) were accumulated to improve the signal to noise ratio of the spectra. Spectra were calibrated using the 520.5 cm 1 line of a silicon wafer. Infrared reflectance spectroscopy As a quick and non-destructive method, infrared reflectance spectra for coral samples were obtained using a Nicolet Nexus 870 FTIR spectrometer with a smart endurance single bounce diamond ATR cell. Spectra over the 4000–525 cm 1 range were obtained by the co-addition of 128 scans with a resolution of 4 cm 1 and a mirror velocity of 0.6329 cm/s. Spectra were coadded to improve the signal to noise ratio. Spectral manipulation such as baseline correction/adjustment and smoothing were performed using the Spectracalc software package GRAMS (Galactic Industries Corporation, NH, USA). Band component analysis was undertaken using the Jandel ‘‘Peakfit’’ software package that enabled the type of fitting function to be selected and allows specific parameters to be fixed or varied accordingly. Band fitting was done using a Lorentzian–Gaussian cross-product function with the minimum number of component bands used for the fitting process. The Lorentzian–Gaussian ratio was maintained at values greater than 0.7 and fitting was undertaken until reproducible results were obtained with squared zcorrelations of r2 greater than 0.99. Results and discussion Minor elements in coral Some selected minor elements in the coral samples, including Li, Mg, Sr, Mn, Fe and U were measured using ICP-MS. These results
Table 1 Concentrations (lg/g) of minor elements selected in the coral growth bands. Sample
Year
Li
Mg
Sr
Mn
Fe
U
XL1-1 XL1-5 XL1-10 XL1-20 XL1-50 XL1-75 XL1-100 XL1-125
2006 2002 1997 1987 1957 1930 1905 1880
0.53 0.42 0.48 0.40 0.52 0.43 0.43 0.47
1175.58 965.82 1017.86 1123.72 1096.67 982.39 877.02 983.67
7865.02 7508.51 7801.90 7452.31 7899.42 6813.50 6675.36 6679.04
1.61 0.76 0.64 0.74 0.84 0.52 0.29 0.58
1280.60 1277.96 1335.07 1342.27 1431.62 1301.72 1296.06 1616.43
2.21 2.87 2.86 2.58 2.76 2.42 2.37 2.37
proved that the Porites coral sample XL1 from South China Sea has high Mg (>800 lg/g) and Sr (>6500 lg/g) concentration (Table 1), which are the most thoroughly studied elements in some benthonic mollusc shells and Cnidarian and skeletal marine minerals [13,15,22,23]. As described earlier, different minor elements such as Sr and Mg, occur in the aragonite skeletons and shells. For example, aragonitic layers with low Sr (<2000 lg/g) and low Mg (<600 lg/g) occur in Bivalvia and Gastropoda [23]; P.venus seashells have low Sr (2000 lg/g) and Mg (200 lg/g) [15]; low Sr (2000 lg/g) and Mg (400 lg/g) contents are also present in Mollusca while high Sr (>6500 lg/g) and Mg (>1500 lg/g) occur in Cnidaria [13]. In the current study, Porites coral samples XL1 has relatively lower Sr and Mg, but higher Fe content than the sample from Malaysia (Table 1) [15]. The concentration of Fe exceeds 1000 lg/g, which is higher than Mg in XL. And the contents of Li, Mn and U are below 3 lg/g (Table 1). Although U content falls into the range reported by previous research [24–26], Mn in XL1 is lower than those in some studies [27–29]. Changes in the contents of these elements at different growth bands could lead to some infrared spectroscopic bands shifts, such as those observed for Sr and Mg [13,18].
Raman spectroscopy The Raman spectroscopy of coral skeleton samples in the 1500– 100 cm 1 spectral range is shown in Fig. 2. The spectra of samples are similar, and consist of a series of sharp peaks, most of which are assigned to the symmetric stretching mode (m1) at 1083 cm 1, inplane bending mode (m4) at 701 and 705 cm 1, and lattice modes at 205 cm 1 and 151 cm 1, which define the peaks of aragonite as described in earlier research [15,17,20,21,30]. In the present work, a very weak Raman band around 1462 cm 1 of aragonite was attributed to the m3 antisymmetric stretching vibrational mode. Therefore, Raman spectra showed that the mineral phase of samples from growth bands is aragonite. As illustrated in Fig. 2, samples from different growth bands of coral skeletons have the same mineral phase. But in the 300– 100 cm 1 region, sample XL1-1 shows some different peaks when compared with the other spectra (Fig. 3). For example, a peak at 132.9 cm 1 was present in the spectrum of XL1-1, but for the other samples this peak shifted to 141 cm 1; and the peak at 178.6 cm 1 for XL1-1 was split into two bands at 179 and 189 cm 1. Raman studies show that another metastable calcium carbonate mineral, vaterite, has a series of peaks attributed to lattice vibrations at 106, 120, 151, 175, 210, 268 and 302 cm 1 [20,31]. Although some studies about the precursors of biogenic carbonate showed that amorphous phase or vaterite occurred as potential precursors [32,33], the peaks for XL1-1 showed a possibility that the aragonitic mineral phase of the skeleton coral was transformed from vaterite. For example, as shown in Fig. 3, the peak at 133 cm 1 in XL1-1 showed a transition phase indicating which peak of vaterite at 120 cm 1 shifts to peak at 141 cm 1 of aragonite. Similarly, the peak at 178 cm 1 in XL1-1 showed a
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transition that indicated that the 175 cm 1 band of vaterite shifted to 179 cm 1 for aragonite. In an earlier research work [17], Huntite showed similar Raman peaks at 118 cm 1, 155 cm 1 and 272 cm 1 to vaterite. But Huntite is Mg-rich carbonate. So we can infer that the Raman shift at the bands between 300 cm 1 and 100 cm 1 seems to arise from lattice change of mineral. And for all Raman spectra of growth bands, a broad weak band at 267 cm 1 seems to show that the band at 268 cm 1 for vaterite weakened to 261 cm 1 for aragonite. Although some previous studies did not come to a firmconclusion about the precursor of biogenic carbonate, lots of reports about the transition of vaterite to aragonite are available in the literature [19,34–36]. In the present work, it is proposed that the vaterite could be the precursor of aragonite phase of coral skeleton from South China Sea. Infrared reflectance spectroscopy and structure composition
Fig. 3. Raman spectra of coral samples in the 100–300 cm 1 region showing the peak at 133 cm 1 for XL 1-1 shifts to peak at 141 cm 1 for other samples.
The infrared reflectance spectra from the growth bands of coral in 600–4000 cm 1 region are reported in Fig. 4. As shown in the Raman spectra, all samples for the different growth bands display the aragonite phase. For the sample in the first layer of the skeleton, the peaks in the 3000–3600 cm 1region, and 2923 cm 1, 2854 cm 1 were attributed to water and organic matter as shown in the spectrum of XL1-1. In the 600–2000 cm 1 region, all spectra clearly showed bands due to aragonite mainly. The intense bands at 1469, 855 cm 1 and the doublet at 712 and 699 cm 1 are assigned to the antisymmetric stretching mode m3, out-of-plane bending mode m2 and in-plane bending mode m4 of CO23 . Symmetric stretching mode m1 occurs at 1082 cm 1 as a low intensity peak, and a combined m1 + m4 mode presents at around 1786 cm 1 as a very weak band described in earlier studies [15]. Otherwise, two low intensity bands at 1665 and 1030 cm 1 in the spectrum of XL1-1 could be assigned to amide [13,18] and (Si)–OH [37], which resulted from the signal of the organic matter and the incorporated impurities; these (Si)–OH impurities could come from eroded soil and marine sediments. As it can be seen in Fig. 4, the positions of stretching and bending modes, such as m1, m2 m3 and m4, change with samples from dif-
Fig. 4. Infrared reflectance spectra of coral samples in the 4000–600 cm
1
region.
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m4 (712 cm ) m2 (855 cm 1) m1 (1082 cm 1) m3 (1469 cm 1) m1 + m4 (1786 cm 1) a b
0.465 0.663 0.384 0.378 0.072
Mg 0.227 0.064 0.288 0.498 0.117
Sr
Mn
0.662 0.458 0.463 0.934a 0.636
0.591 0.441 0.627 0.465 0.016
Fe 0.553 0.410 0.749b 0.486 0.292
U 0.26 0.062 0.145 0.639 0.937a
Correlation is significant at the 0.01 level (2-tailed). Correlation is significant at the 0.05 level (2-tailed).
ferent growth bands of the aragonitic skeleton. According to Böttcher et al., in natural inorganic or organic Mg calcite, Mg2+ content has a linear correlation with the position of m4 band of Mg calcite as observed at 711 cm 1 [17,38]. Some previous research also studied the cation substitution in carbonate system, like Calcite– Magnesite–siderite–rhodochrosite [39–41] and CdCO3 [42]. Positive correlation between Sr2+, Mg2+ content and m4 position of biogenic calcite was also studied by Dauphin [18]. In Dauphin’s other work [13], Sr2+, Mg2+ in aragonitic skeletons of marine geological materials showed negative correlation with m2 band between 856–866 cm 1. But in Raman spectroscopic investigation of carbonates system [43], Mg contents of different carbonates showed a positive correlation in Raman shifts for m1, m2, m3 and m4 bands. In the current work, it is shown that with the exception of Fe, some minor elements including Li, Mg, Sr, Mn and U have negative correlation with the main peaks in infrared spectra of samples (Table 2). In comparison with earlier research, Mg does not show significant correlation with the m2 band. Besides the shift of m2 and m4 bands, the minor elements have significant correlation with m3 and m1 bands. As shown in Table 2, Li shows a high negative correlation with m2 band (855 cm 1) (r = 0.663), while Sr and Mn show similar negative correlation with m4 band (712 cm 1) (r = 0.662 and r = 0.591 respectively). Mn also shows a negative correlation with m1 band (1082 cm 1) (r = 0.627). But in comparison with other research work [39], Mn concentration in carbonate system showed positive correlation with m4 band and negative correlation with m2 band in infrared spectroscopy, respectively. Mg and U are negatively correlated with m3 band (1469 cm 1) (r = 0.498 and r = 0.639) as Sr (r = 0.934), which is different from the results obtained in previous research work [13,18]. For U, a significantly negative correlation with m1 + m4 band (1786 cm 1) is observed (r = 0.937). It is shown that Fe is an exception in that it has positive correlation with m1, m2, m3, m4 and m1 + m4 bands, and a significant correlation with m1 band (1082 cm 1) (r = 0.749). A similar phenomenon occurred in siderite–magnesite system [40], in which Fe content is correlated positively with m2, but negatively with m3 and m4. With respect to the Raman spectra of carbonates [43], the Fe content in carbonates also showed positive correlation with m3 and m4 Raman shifts. Although different results are observed, the correlation of the composition of minor elements with bands shift in infrared of aragonitic skeleton samples of coral demands further study. Meanwhile prediction models of Sr, Mg and U in coral growth bands could be constructed through bands shifts in infrared spectroscopy, which will be a quick method to build a model for understanding climate change and reconstruction of paleoclimate [44–46]. Conclusions Characteristics of carbonate samples from different growth bands of Porites coral skeletons were studied by Raman spectroscopy, infrared reflectance spectroscopy and infrared emission spectroscopy. Raman spectra for samples showed that coral skeleton consists of aragonite, but the ‘‘youngest’’ samples XL1-1 shows
a probable transition phase of vaterite to aragonite, which provides evidence that vaterite is a precursor of skeletal aragonite of Porites coral. Shifts in the main bands, including m3 (1469 cm 1), m1 (1082 cm 1), m2 (855 cm 1) and m4 (712 cm 1) bands in infrared spectra for skeleton samples indicate that the variation of minor elements contents in different growth bands could influence the characteristic positions of CO23 in the infrared spectra. In particular, Mg, Sr and U have significant correlation with the positional shift of the antisymmetric stretching band m3 (1469 cm 1). Li shows a high negative correlation with m2 band (855 cm 1) and Mn shows a negative correlation with m1 band (1082 cm 1). A significantly negative correlation is observed for U with m1 + m4 band (1786 cm 1). As an exception, Fe has a positive correlation with m1, m2, m3, m4 and m1 + m4 bands shifts, especially a significant correlation with m1 band (1082 cm 1). Acknowledgements This work was funded by the National Key Basic Research Program of China (Nos. 2013CB956102 and 2010CB950101), the ‘‘Strategic Priority Research Program’’ of the Chinese Academy of Sciences (Grant No. XDA05080301), the National Natural Science Foundation of China (Nos. 40830852, 41025007 and 41203074), and an Australian Research Councile discovery project (DP0773081). And Queensland University of Technology, School of Chemistry, Physics and Mechanical Engineering and the University of Queensland, Radiogenic Isotope Facility (RIF) lab of Centre for Microscopy and Microanalysis (CMM) supply technical support. The assistance of Yunfei Xi and Haibo Liu at Queensland University of Technology, is gratefully acknowledged.
References [1] M.M. Scott, Young Oxford Book of Ecology, Oxford University Press, Oxford, UK, 1994. [2] A. Suzuki, H. Kawahata, in: M. Shiyomi, H. Kawahata, H. Koizumi, A. Tsuda, Y. Awaya (Eds.), Global Environmental Change in the Ocean and on Land, Terrapub, Tokyo, 2004, pp. 229–248. [3] L. Nothdurft, G. Webb, Facies 53 (2007) 1–26. [4] S.A. Wainwright, Exp. Cell Res. 34 (1964) 213–230. [5] J.H. Vandermeulen, N. Watabe, Mar. Biol. 23 (1973) 47–57. [6] G. Guillemin, J.L. Patat, J. Fournie, M. Chetail, J. Biomed. Mater. Res. 21 (1987) 557–567. [7] J.M. Lough, D.J. Barnes, J. Exp. Mar. Biol. Ecol. 135 (1990) 35–57. [8] D.W. Knutson, R.W. Buddemeier, S.V. Smith, Science 177 (1972) 270. [9] T.P. Scoffin, A.W. Tudhope, B.E. Brown, H. Chansang, R.F. Cheeney, Coral Reefs 11 (1992) 1–11. [10] M.W. Miller, Mar. Ecol. Prog. Ser. 122 (1995) 217–225. [11] T.F. Goreau, Biol. Bull. 116 (1959) 59–75. [12] C. Langdon, T. Takahashi, C. Sweeney, D. Chipman, J. Goddard, F. Marubini, H. Aceves, H. Barnett, M.J. Atkinson, Global Biogeochem. Cycles 14 (2000) 639– 654. [13] Y. Dauphin, Appl. Spectrosc. 51 (1997) 253–258. [14] B. Kaczorowska, A. Hacura, T. Kupka, R. Wrzalik, E. Talik, G. Pasterny, A. Matuszewska, Anal. Bioanal. Chem. 377 (2003) 1032–1037. [15] F.Z. Zakaria, J. Mihály, I. Sajó, R. Katona, L. Hajba, F.A. Aziz, J. Mink, J. Raman Spectrosc. 39 (2008) 1204–1209. [16] W.D. Bischoff, S.K. Sharma, F.T. Mackenzie, Am. Mineral. 70 (1985) 581–589.
100
Y. Song et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 112 (2013) 95–100
[17] H.G.M. Edwards, S.E.J. Villar, J. Jehlicka, T. Munshi, Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 61 (2005) 2273–2280. [18] Y. Dauphin, Appl. Spectrosc. 53 (1999) 184–190. [19] B. Hasse, H. Ehrenberg, J.C. Marxen, W. Becker, M. Epple, Chem. A European J. 6 (2000) 3679–3685. [20] U. Wehrmeister, A.L. Soldati, D.E. Jacob, T. Häger, W. Hofmeister, J. Raman Spectrosc. 41 (2010) 193–201. [21] J. Urmos, S.K. Sharma, F.T. Mackenzie, Am. Mineral. 76 (1991) 641–646. [22] H.W. van der Marel, Atlas of Infrared Spectroscopy of Clay Minerals and Their Admixtures, Elsevier Scientific Publication, Co., Amsterdam, 1976. [23] Y. Dauphin, A. Denis, Compar. Biochem.Phys. – Part A: Molec. amp Integr. Phys. 126 (2000) 367–377. [24] G. Thompson, H.D. Livingston, Earth Planet. Sci. Lett. 8 (1970) 439–442. [25] P.K. Swart, J.A.E.B. Hubbard, Coral Reefs 1 (1982) 13–19. [26] G. Wei, M. Sun, X. Li, B. Nie, Palaeogeogr., Palaeocl., Palaeogeogr. 162 (2000) 59–74. [27] Z. Peng, J. Liu, C. Zhou, B. Nie, T. Chen, Chin. J. Geochem. 25 (2006) 132–138. [28] S.A. Al-Rousan, R.N. Al-Shloul, F.A. Al-Horani, A.H. Abu-Hilal, Mar. Pollut. Bull. 54 (2007) 1912–1922. [29] N. Jayaraju, B.C.S.R. Reddy, K. Reddy, Soil Sediment Contam. 18 (2009) 445– 454. [30] V.C. Farmer, The Infrared Spectra Of Minerals Mineralogical Society Monograph, Mineralogical Society London, 1974. [31] R.W. Gauldie, S.K. Sharma, E. Volk, Comp. Biochem. Physiol. A Physiol. 118 (1997) 753–757.
[32] S. Weiner, J. Mahamid, Y. Politi, Y. Ma, L. Addadi, Front. Mater. Sci. China 3 (2009) 104–108. [33] P.L. Clode, K. Lema, M. Saunders, S. Weiner, Coral Reefs 30 (2011) 1–8. [34] Q. Shen, L. Wang, Y. Huang, J. Sun, H. Wang, Y. Zhou, D. Wang, J. Phys. Chem. B 110 (2006) 23148–23153. [35] W. Bao, H. Li, Y. Zhang, Cryst. Res. Technol. 44 (2009) 395–401. [36] A. Sarkar, S. Mahapatra, Cryst. Growth Des. 10 (2010) 2129–2135. [37] N. Kovacˇ, J. Gaganeli, O. Bajt, B. Orel, A. Šurca Vuk, RMZ-Mater Geoenviron. 52 (2005) 81–85. [38] M.E. Böttcher, P.-L. Gehlken, D.F. Steele, Solid State Ionics 101–103 (2) (1997) 1379–1385. [39] M.E. Böttcher, P.L. Gehlken, E. Usdowski, Contr. Mineral. Petrol. 109 (1992) 304–306. [40] J.V. Dubrawski, A.L. Channon, S.S.J. Warne, Am. Mineral. 74 (1989) 187–190. [41] M.E. Böttcher, P.-L. Gehlken, Neues Jahrb. Mineral. Abh. 169 (1995) 81–95. [42] M.E. Böttcher, P.-L. Gehlken, Appl. Spectrosc. 51 (1997) 130–131. [43] N. Rividi, M. van Zuilen, P. Philippot, B. Menez, G. Godard, E. Poidatz, Astrobiology 10 (2010) 293–309. [44] J.W. Beck, R.L. Edwards, E. Ito, F.W. Taylor, J. Recy, F. Rougerie, P. Joannot, C. Henin, Science 257 (1992) 644–647. [45] T. Mitsuguchi, E. Matsumoto, O. Abe, T. Uchida, P.J. Isdale, Science 274 (1996) 961–963. [46] K.-F. Yu, J.-X. Zhao, G.-J. Wei, X.-R. Cheng, T.-G. Chen, T. Felis, P.-X. Wang, T.-S. Liu, Palaeogeogr., Palaeoclimatol., Palaeoecol. 218 (2005) 57–73.