- Email: [email protected]
Marine productivity response to abrupt climate changes: a model study
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Abstracts / Quaternary International 279-280 (2012) 233–345
Also some NPP were found, like for example Chlamidospores, which is good indicator for locally dry, and also mesotrophic conditions. The results are promising to reconstruct even with details the burial rituals and involved in it plant material. MARINE PRODUCTIVITY RESPONSE TO ABRUPT CLIMATE CHANGES: A MODEL STUDY Véronique Mariotti. LSCE, France E-mail address: [email protected]
Marine sediments have revealed large and significant variations in marine productivity during glacial periods, with abrupt variations especially observed during Heinrich events. Here, we study the response of marine biogeochemistry to such an event. To do so, we use a biogeochemical model of the global ocean, PISCES, coupled to the atmosphere ocean general circulation model IPSL_CM4. Two 500-year simulations are presented here: one control run equilibrated in glacial state and one transient run in which a freshwater forcing of 0.1Sv has been applied to the North Atlantic to mimic the behavior of a Heinrich event. We find that primary productivity and organic carbon export greatly decrease overall (-15% for both) during a Heinrich event, albeit with large regional variations. The North Atlantic displays a significant decrease, whereas the Southern Ocean shows an increase, in agreement with paleoproductivity reconstructions. In the Equatorial Pacific, our model simulates an increase in organic matter export production but decreased biogenic silica export. This complex behavior results from changes in relative uptake of Si and C by diatoms and appears to be in agreement with some recent marine records. We will also investigate how these changes in productivity may translate to changes in ocean fluxes of greenhouse gases (CO2, N2O). PALAEOENVIRONMENT AND LAND-USE IN PADUA (NORTH-EASTERN ITALY) DURING THE IRON AGE: INTRA-SITU ARCHAEOBOTANICAL ANALYSIS
The Middle Pleistocene glacial deposits with megabreccia facies occur at many locations at altitudes between 1 m and 800 m a.s.l. within the study area, which includes northern Adriatic islands (Krk, Rab, Pag) and coastal zone of the southwest Croatian mainland (Southern Velebit Mts.(Velika Paklenica) and Northern Dalmatia (Zdrilo, Novigrad Sea coast, Obrovac)). The megabreccias are erosional remnants of terminal, basal and lateral dump moraines. They occur in association with kame-terrace deposits (Baska valley on Krk island and Velika Paklenica) or with proglacial fluvial or lacustrine sediments (Novigrad Sea coast and Zdrilo Cove). Their main characteristics are extra large limestone boulders and megablocks that “float” in the coarse-grained “matrix”. The boulders are commonly 1 to 10 m in diametre, but their maximum size is nearly 25 m. Boulders are subrounded to medium rounded, faceted with rounded keels and usually polished. Many have preserved glacial striae. Their orientation is usually random, although preferred orientation showing push direction has been noticed in Velika Paklenica, Zdrilo and Novigrad Sea coastal section. Some boulders show fossil karren of preglacial karstification. The “matrix” is poorly to well cemented polymict breccia with medium grain size from 9 to 10 cm. Smaller boulders up to 50 cm are also frequent. Crushed or fractured limestone clasts are common. The megabreccias are completely unsorted. During ice retreat this poorly packed sediment was firstly washed out by meltwaters and later filled again with finer sediment. Water trapped in interspaces locally produced calcite cement. Erosional contact with underlying severely disturbed glaciolacustrine sediments is visible at Zdrilo. The basal moraine on Krk island show gradual transition to glaciofluvial deposits of extensive kame-terrace. The primary origin of megablocs may also be result of a major earthquake, and then entrainment by ice. LANDSCAPE RECONSTRUCTION AND ARCHAEOLOGICAL PREDICTION IN THE LAKE MANYARA AREA, NORTHERN TANZANIA Michael Märker. Heidelberg Academy of Sciences and Humanities c/o , Germany E-mail address: [email protected]
Michele Maritan. Dept. of Geography - University, Italy E-mail address: [email protected]
Microscopic plant remains such as pollen grains and seeds/fruits from archaeological sites, can significantly increase our understanding of past human activities. Indeed they are the documents of the past environment and land-use. They are very often considered in a multidisciplinary approach to the study of an archaeological site. With this aim we investigated the infilling of a small ditch buried at the bottom of a ca. 4 m thick sequence of archaeological deposits in the city centre of Padua (North-eastern Italy). This research was carried out within the project “Padova Underground: a geoarchaeological investigation of the city”, funded by Fondazione Cariparo. Sediments were sampled through a mechanical coring carried out for geotechnical purposes. This is the first integrated analysis of both pollen and seed/fruits carried out in the city centre. Early settlements in Padua date to the late Bronze Age. In the Iron Age Padua developed as an important urban centre, which later became a Roman Municipium. The stratigraphy of the coring indicate that the analysed sediments most probably date to the Iron Age, and a radiocarbon dating will soon be available. The coring site is well inside the ancient inhabited area where many archaeological records are available from the 9th century to the beginning of the Roman age. The pollen record is characterized by the dominance of herb vegetation. The high percentage of cereals’ pollen and the co-occurrence of seeds and of their weeds (pollen and seeds) suggest the presence of cultivation quite near the coring site and therefore inside the inhabited area. The occurrence of pollen and seeds of a variety of ruderal plants is in agreement with the presence of settlements nearby. The hygrophilous plants (herbs, trees and shrubs) are quite rare, therefore the soils should have been well drained and suitable for cultivation and dwelling. THE MEGABRECCIA FACIES OF THE MIDDLE PLEISTOCENE GLACIAL DEPOSITS OF THE SOUTHWEST CROATIA Ljerka Marjanac. Institute of Quaternary Paleontology and Geology, , Croatia (Hrvatska) E-mail address: [email protected]
In this study we focus on archaeological sites in the area of Lake Manyara and the Makuyuni river basin, Northern Tanzania. This region is known for Middle and Lower Pleistocene fossil finds and artefacts. Non invasive field methods were used to characterize environmental variables for the prediction of archaeological sites. In particular detailed information especially on the distribution of soils and substrates are measured along typical transects. We applied sophisticated statistical methods to regionalize the given information. The methodology considers not only the characteristics of specific transects but implicitly also the related pedogenetic and morphogenetic processes. To analyze the spatial distribution of potential archaeological find locations we applied a methodology based on statistical mechanics. This method is able to handle presence-only datasets such as the archaeological find locations. The spatial distributions of the find locations were collected in literature and by own field work over the last years. For the modeling we utilized environmental information such as spatially continuous layer of soils and substrates, topography (30m SRTM DEM), vegetation information as well as ASTER multispectral data as predictor variables. The results reveal potential areas where further fossil sites may be located. The prediction is validated by fieldwork. All the data are stored in the ROCEEH Out of Africa Database (ROAD). ANCIENT DNA ANALYSIS AS A TOOL TO IDENTIFY SIBLING SPECIES IN THE QUATERNARY FOSSIL RECORD: A CASE STUDY IN MICROTUS ARVALIS AND MICROTUS ROSSIAEMERIDIONALIS (ARVICOLINAE, RODENTIAE) Evgenia Markova. Institute of Plant and Animal Ecology the Ural Bra, Russian Federation E-mail address: [email protected]
Specific identification of Quaternary micromammals traditionally relies upon morphology. Sibling species that are extremely similar in appearance but are nonetheless reproductively isolated appear to be the most problematic to identify in the fossil record. Nowadays, ancient DNA analysis
Abstracts / Quaternary International 279-280 (2012) 233–345
Also some NPP were found, like for example Chlamidospores, which is good indicator for locally dry, and also mesotrophic conditions. The results are promising to reconstruct even with details the burial rituals and involved in it plant material. MARINE PRODUCTIVITY RESPONSE TO ABRUPT CLIMATE CHANGES: A MODEL STUDY Véronique Mariotti. LSCE, France E-mail address: [email protected]
Marine sediments have revealed large and significant variations in marine productivity during glacial periods, with abrupt variations especially observed during Heinrich events. Here, we study the response of marine biogeochemistry to such an event. To do so, we use a biogeochemical model of the global ocean, PISCES, coupled to the atmosphere ocean general circulation model IPSL_CM4. Two 500-year simulations are presented here: one control run equilibrated in glacial state and one transient run in which a freshwater forcing of 0.1Sv has been applied to the North Atlantic to mimic the behavior of a Heinrich event. We find that primary productivity and organic carbon export greatly decrease overall (-15% for both) during a Heinrich event, albeit with large regional variations. The North Atlantic displays a significant decrease, whereas the Southern Ocean shows an increase, in agreement with paleoproductivity reconstructions. In the Equatorial Pacific, our model simulates an increase in organic matter export production but decreased biogenic silica export. This complex behavior results from changes in relative uptake of Si and C by diatoms and appears to be in agreement with some recent marine records. We will also investigate how these changes in productivity may translate to changes in ocean fluxes of greenhouse gases (CO2, N2O). PALAEOENVIRONMENT AND LAND-USE IN PADUA (NORTH-EASTERN ITALY) DURING THE IRON AGE: INTRA-SITU ARCHAEOBOTANICAL ANALYSIS
The Middle Pleistocene glacial deposits with megabreccia facies occur at many locations at altitudes between 1 m and 800 m a.s.l. within the study area, which includes northern Adriatic islands (Krk, Rab, Pag) and coastal zone of the southwest Croatian mainland (Southern Velebit Mts.(Velika Paklenica) and Northern Dalmatia (Zdrilo, Novigrad Sea coast, Obrovac)). The megabreccias are erosional remnants of terminal, basal and lateral dump moraines. They occur in association with kame-terrace deposits (Baska valley on Krk island and Velika Paklenica) or with proglacial fluvial or lacustrine sediments (Novigrad Sea coast and Zdrilo Cove). Their main characteristics are extra large limestone boulders and megablocks that “float” in the coarse-grained “matrix”. The boulders are commonly 1 to 10 m in diametre, but their maximum size is nearly 25 m. Boulders are subrounded to medium rounded, faceted with rounded keels and usually polished. Many have preserved glacial striae. Their orientation is usually random, although preferred orientation showing push direction has been noticed in Velika Paklenica, Zdrilo and Novigrad Sea coastal section. Some boulders show fossil karren of preglacial karstification. The “matrix” is poorly to well cemented polymict breccia with medium grain size from 9 to 10 cm. Smaller boulders up to 50 cm are also frequent. Crushed or fractured limestone clasts are common. The megabreccias are completely unsorted. During ice retreat this poorly packed sediment was firstly washed out by meltwaters and later filled again with finer sediment. Water trapped in interspaces locally produced calcite cement. Erosional contact with underlying severely disturbed glaciolacustrine sediments is visible at Zdrilo. The basal moraine on Krk island show gradual transition to glaciofluvial deposits of extensive kame-terrace. The primary origin of megablocs may also be result of a major earthquake, and then entrainment by ice. LANDSCAPE RECONSTRUCTION AND ARCHAEOLOGICAL PREDICTION IN THE LAKE MANYARA AREA, NORTHERN TANZANIA Michael Märker. Heidelberg Academy of Sciences and Humanities c/o , Germany E-mail address: [email protected]
Michele Maritan. Dept. of Geography - University, Italy E-mail address: [email protected]
Microscopic plant remains such as pollen grains and seeds/fruits from archaeological sites, can significantly increase our understanding of past human activities. Indeed they are the documents of the past environment and land-use. They are very often considered in a multidisciplinary approach to the study of an archaeological site. With this aim we investigated the infilling of a small ditch buried at the bottom of a ca. 4 m thick sequence of archaeological deposits in the city centre of Padua (North-eastern Italy). This research was carried out within the project “Padova Underground: a geoarchaeological investigation of the city”, funded by Fondazione Cariparo. Sediments were sampled through a mechanical coring carried out for geotechnical purposes. This is the first integrated analysis of both pollen and seed/fruits carried out in the city centre. Early settlements in Padua date to the late Bronze Age. In the Iron Age Padua developed as an important urban centre, which later became a Roman Municipium. The stratigraphy of the coring indicate that the analysed sediments most probably date to the Iron Age, and a radiocarbon dating will soon be available. The coring site is well inside the ancient inhabited area where many archaeological records are available from the 9th century to the beginning of the Roman age. The pollen record is characterized by the dominance of herb vegetation. The high percentage of cereals’ pollen and the co-occurrence of seeds and of their weeds (pollen and seeds) suggest the presence of cultivation quite near the coring site and therefore inside the inhabited area. The occurrence of pollen and seeds of a variety of ruderal plants is in agreement with the presence of settlements nearby. The hygrophilous plants (herbs, trees and shrubs) are quite rare, therefore the soils should have been well drained and suitable for cultivation and dwelling. THE MEGABRECCIA FACIES OF THE MIDDLE PLEISTOCENE GLACIAL DEPOSITS OF THE SOUTHWEST CROATIA Ljerka Marjanac. Institute of Quaternary Paleontology and Geology, , Croatia (Hrvatska) E-mail address: [email protected]
In this study we focus on archaeological sites in the area of Lake Manyara and the Makuyuni river basin, Northern Tanzania. This region is known for Middle and Lower Pleistocene fossil finds and artefacts. Non invasive field methods were used to characterize environmental variables for the prediction of archaeological sites. In particular detailed information especially on the distribution of soils and substrates are measured along typical transects. We applied sophisticated statistical methods to regionalize the given information. The methodology considers not only the characteristics of specific transects but implicitly also the related pedogenetic and morphogenetic processes. To analyze the spatial distribution of potential archaeological find locations we applied a methodology based on statistical mechanics. This method is able to handle presence-only datasets such as the archaeological find locations. The spatial distributions of the find locations were collected in literature and by own field work over the last years. For the modeling we utilized environmental information such as spatially continuous layer of soils and substrates, topography (30m SRTM DEM), vegetation information as well as ASTER multispectral data as predictor variables. The results reveal potential areas where further fossil sites may be located. The prediction is validated by fieldwork. All the data are stored in the ROCEEH Out of Africa Database (ROAD). ANCIENT DNA ANALYSIS AS A TOOL TO IDENTIFY SIBLING SPECIES IN THE QUATERNARY FOSSIL RECORD: A CASE STUDY IN MICROTUS ARVALIS AND MICROTUS ROSSIAEMERIDIONALIS (ARVICOLINAE, RODENTIAE) Evgenia Markova. Institute of Plant and Animal Ecology the Ural Bra, Russian Federation E-mail address: [email protected]
Specific identification of Quaternary micromammals traditionally relies upon morphology. Sibling species that are extremely similar in appearance but are nonetheless reproductively isolated appear to be the most problematic to identify in the fossil record. Nowadays, ancient DNA analysis