- Email: [email protected]
Enigma of the Middle Valdayn
552
Abstracts / Quaternary International 279-280 (2012) 462–565
climate change by virtue of alternations of aeolian sand and sandy soil, which corresponded to aridity and humidity conditions, respectively. In this desert, there is a set of contrastive deposits made up of loose sand and overlying dark sandy soil just below land surface. Optical dating using SAR technique with quartz was applied to the deposits. The results indicate that the developed soil and underlying deep aeolian sand are responses to the Holocene optimum (H.O.) and the last late glacial, respectively. The rough extension of last late glacial sand was revealed by studying about 26 profiles. Combined with studies of grain-size, magnetic susceptibility and sediment color, the environment of the desert is reconstructed. The results suggest that the mobile sand was stabilized and contracted gradually when approaching Holocene. It was completely covered by vegetation in H.O. With rivers and lakes inside Otindag Desert developed the water level of them has lowered in the dry and cold environment of the glacial stage and the rivers and lakes subjected to wind erosion and reform has provided the enlargement of drift sand with material resources. ENIGMA OF THE MIDDLE VALDAYN Lavrushin Yuri. Moscow, Russian Federation E-mail address: [email protected]
The Middle Valdayn (Middle Würm) is a non-glacial interval of the Late Pleistocene. A paleoclimatic situation of the Russian Plain was characterized by instable climatic conditions, alternation of thermochrons and cryochrons, and absence of zonal vegetation type even in the warmest time intervals. Trends of environmental changes in the Russian Plain were formed under a great influence of the Atlantic-Arctic oceanic climatic “machine”. The important components of the “machine” were advections of the Atlantic waters (AAW) into the Arctic Ocean and those of the polar waters (APW) into the Atlantic Ocean. The AAW promoted destruction of the ice cover in the ocean and the warming in the land. The APW brought into the Atlantic not only the polar waters but large masses of sea ice. This changed the water structure, diminished an influence of the warm Gulf Stream, and caused great changes in tachyhalyne circulation in the Atlantic Ocean. In addition, the western transportation of air masses appeared to be significantly different from that of interglacials. Palynological data show that the Russian Plain environments were affected by the air masses from Siberia (during thermochrons), Middle Asia and the Arctic (during cryochrons). The appearance of “ice glaciation” in the Atlantic Ocean provided specific non-glacial climatic conditions both in the Russian Plain and Europe. At present welldefined correlations between different advections and environmental changes in the Russian Plain are geochronologically controlled. TERMINAL PALEOLITH ENVIRONMENTAL EVENTS IN THE DIVNOGOR'E REGION (MIDDLE DON RIVER) Lavrushin Yuri. Moscow, Russian Federation E-mail address: [email protected]
Studies of the archaeological object Divnogor'e-9 revealed a succession of environmental events of the terminal Late Pleistocene. The object is located at the mouth of ravine which cut the Central Russian Upland margin formed by chalk. Deposits of the ravine widening compose three units. The lower unit is represented by alternating sediments of mud flows and basins. At the sediment contacts there are rich accumulations of bones and skeletons of Equus cabbalus. The unit includes five levels of bone accumulations; level 5 is dated at about 14 ka, ages of the other levels are estimated from 13,5 to 13,0 ka. Level 3 contains a working landing with numerous siliceous artefacts. Many horses came to the ravine because the basins contained a lot of dissolved chalk which was dainties for them. Mud flows from heavy rains caused death of horses. The middle unit of landfall and detrital deposits was most likely formed due to seismic processes. The upper unit of slope diluvium contains two buried soils. A top of the lower soils is represented by wood coal. This may evidence for a local fire caused by an activity of an ancient man. The upper soil contains wood pollen. The most favorable conditions for diluvium formation are provided by light rains, which wash out the deposits. The buried soils reflect breaks of the process. During the formation of diluvium and mudflows herbal vegetation dominated.
A model of deposition of the lower unit was prepared and a specific technique of hunting of ancient man was reconstructed. ANALYSIS OF VEGETATION AND ENVIRONMENTAL CHANGES SINCE 11.5 KY BP FROM EXTINCT OXBOW LAKE, FLOOD PLAIN OF THE ELBE RIVER, CZECH REPUBLIC Pavla Zácková. Charles University in Prague, Faculty of Nature Sc, Czech Republic E-mail address: [email protected]
The Late Glacial palaeomeander Chrast is situated in the area of the middle Elbe river floodplain, where a huge number of paleomeanders of the Holocene age are preserved. This area is typical for a presence of the unique complex of the relict wetlands and fen meadows, which used to be widely spread in the Holocene. Presented research is a part of large multi-proxy project dealing on coevolution of human impact and natural processes of the landscape in this region during the Late Quaternary. Investigated profile (total depth 285 cm) was obtained from an oxbow lake. Plant macro and micro-fossils were studied with supportive evidences from geochemical and sedimentological data. Based on the results profile was divided into 5 zones (A1-A5). Last 110 cm (A1-A3) contains the unique record of Allerød vegetation. Sediment of the base of the palaeomeander (11 450 60 BP) contain record of macrophyte vegetation (Nuphar lutea, Batrachium, Potamogeton ssp). The local pollen spectra give an evidence of occurrence of aquatic species (Myriophyllum spicatum - type, Pediastrum, Sparganium/Typha angustifolia). Subsequently organic production increased rapidly during 11 523 120 BP (A2) and shallow lake was filled in. This is supported by presence of macroremains of Carex vesiraria/rostrata, C. riparia, Menyanthes trifoliata. Salix, Betula and Pinus wood fragments were also recorded indicating presence of birch-pine forest with intermingle of a spruce. Fires, which were frequent during the end of the Last Glacial, are documented by the record of a large number of burned seeds and charcoal. Calcium carbonate accumulations of the lake marl originated at the beginning of the Younger Dryas (11 010 60 BP). Increased sand deposits (A4) indicate a change from meandering type of the river to the braided one. The end of the sand deposition might be linked with the Glacial/ Holocene transition phase. Local human impact (A5) is documented in the middle of the Holocene (6510 40 BP). HIGH-RESOLUTION RECONSTRUCTION OF CLIMATE AND ENVIRONMENTAL HISTORY DURING FUNNEL-BEAKER CULTURE TIME BASED ON ANNUALLY LAMINATED LAKE SEDIMENTS OF LAKE BELAU AND LAKE POGGENSEE (NORTHERN GERMANY) Jürgen Zahrer. University Kiel, Institute for Ecosystem Research, Germany E-mail address: [email protected]
Synchronous deposition patterns of varves of two lakes in northern Germany were used to reconstruct climate history during the Funnelbeaker culture in north central Europe (5200-6900 cal BP) based on microfacies analysis. The onset of agricultural land use in the catchment areas of these lakes has been detected, too. The dating and synchronisation of the sequences are carried out by radiocarbon dating, tephrochronology and the varve chronology. For climate reconstruction a group of comparative indicators was applied: 1.) thickness of annual layers and the seasonal sub-laminae. 2.) palaeolimnologic-paleoclimatic indicators: Diatoms (genera), Phacotus spec., Crysophytes, autochthonous carbonate precipitation, detrital reworked carbonates, organic and minerogenic input.
A phase of cooler climatic conditions from 6050-5850 cal BP was detected and might reflect the known climatic event of the northern hemisphere (Bond event 4). The high temporal resolution enabled a further zoning: Besides four phases characterised by cold conditions a short, warm and dry phase was detected. Simultaneously, enrichment in minerogenic components and charcoal, preceding the onset of distinct settlement indicators for centuries, might suggest slope instability caused by natural forest fires. The following millenium showed indication for warmer climatic
Abstracts / Quaternary International 279-280 (2012) 462–565
climate change by virtue of alternations of aeolian sand and sandy soil, which corresponded to aridity and humidity conditions, respectively. In this desert, there is a set of contrastive deposits made up of loose sand and overlying dark sandy soil just below land surface. Optical dating using SAR technique with quartz was applied to the deposits. The results indicate that the developed soil and underlying deep aeolian sand are responses to the Holocene optimum (H.O.) and the last late glacial, respectively. The rough extension of last late glacial sand was revealed by studying about 26 profiles. Combined with studies of grain-size, magnetic susceptibility and sediment color, the environment of the desert is reconstructed. The results suggest that the mobile sand was stabilized and contracted gradually when approaching Holocene. It was completely covered by vegetation in H.O. With rivers and lakes inside Otindag Desert developed the water level of them has lowered in the dry and cold environment of the glacial stage and the rivers and lakes subjected to wind erosion and reform has provided the enlargement of drift sand with material resources. ENIGMA OF THE MIDDLE VALDAYN Lavrushin Yuri. Moscow, Russian Federation E-mail address: [email protected]
The Middle Valdayn (Middle Würm) is a non-glacial interval of the Late Pleistocene. A paleoclimatic situation of the Russian Plain was characterized by instable climatic conditions, alternation of thermochrons and cryochrons, and absence of zonal vegetation type even in the warmest time intervals. Trends of environmental changes in the Russian Plain were formed under a great influence of the Atlantic-Arctic oceanic climatic “machine”. The important components of the “machine” were advections of the Atlantic waters (AAW) into the Arctic Ocean and those of the polar waters (APW) into the Atlantic Ocean. The AAW promoted destruction of the ice cover in the ocean and the warming in the land. The APW brought into the Atlantic not only the polar waters but large masses of sea ice. This changed the water structure, diminished an influence of the warm Gulf Stream, and caused great changes in tachyhalyne circulation in the Atlantic Ocean. In addition, the western transportation of air masses appeared to be significantly different from that of interglacials. Palynological data show that the Russian Plain environments were affected by the air masses from Siberia (during thermochrons), Middle Asia and the Arctic (during cryochrons). The appearance of “ice glaciation” in the Atlantic Ocean provided specific non-glacial climatic conditions both in the Russian Plain and Europe. At present welldefined correlations between different advections and environmental changes in the Russian Plain are geochronologically controlled. TERMINAL PALEOLITH ENVIRONMENTAL EVENTS IN THE DIVNOGOR'E REGION (MIDDLE DON RIVER) Lavrushin Yuri. Moscow, Russian Federation E-mail address: [email protected]
Studies of the archaeological object Divnogor'e-9 revealed a succession of environmental events of the terminal Late Pleistocene. The object is located at the mouth of ravine which cut the Central Russian Upland margin formed by chalk. Deposits of the ravine widening compose three units. The lower unit is represented by alternating sediments of mud flows and basins. At the sediment contacts there are rich accumulations of bones and skeletons of Equus cabbalus. The unit includes five levels of bone accumulations; level 5 is dated at about 14 ka, ages of the other levels are estimated from 13,5 to 13,0 ka. Level 3 contains a working landing with numerous siliceous artefacts. Many horses came to the ravine because the basins contained a lot of dissolved chalk which was dainties for them. Mud flows from heavy rains caused death of horses. The middle unit of landfall and detrital deposits was most likely formed due to seismic processes. The upper unit of slope diluvium contains two buried soils. A top of the lower soils is represented by wood coal. This may evidence for a local fire caused by an activity of an ancient man. The upper soil contains wood pollen. The most favorable conditions for diluvium formation are provided by light rains, which wash out the deposits. The buried soils reflect breaks of the process. During the formation of diluvium and mudflows herbal vegetation dominated.
A model of deposition of the lower unit was prepared and a specific technique of hunting of ancient man was reconstructed. ANALYSIS OF VEGETATION AND ENVIRONMENTAL CHANGES SINCE 11.5 KY BP FROM EXTINCT OXBOW LAKE, FLOOD PLAIN OF THE ELBE RIVER, CZECH REPUBLIC Pavla Zácková. Charles University in Prague, Faculty of Nature Sc, Czech Republic E-mail address: [email protected]
The Late Glacial palaeomeander Chrast is situated in the area of the middle Elbe river floodplain, where a huge number of paleomeanders of the Holocene age are preserved. This area is typical for a presence of the unique complex of the relict wetlands and fen meadows, which used to be widely spread in the Holocene. Presented research is a part of large multi-proxy project dealing on coevolution of human impact and natural processes of the landscape in this region during the Late Quaternary. Investigated profile (total depth 285 cm) was obtained from an oxbow lake. Plant macro and micro-fossils were studied with supportive evidences from geochemical and sedimentological data. Based on the results profile was divided into 5 zones (A1-A5). Last 110 cm (A1-A3) contains the unique record of Allerød vegetation. Sediment of the base of the palaeomeander (11 450 60 BP) contain record of macrophyte vegetation (Nuphar lutea, Batrachium, Potamogeton ssp). The local pollen spectra give an evidence of occurrence of aquatic species (Myriophyllum spicatum - type, Pediastrum, Sparganium/Typha angustifolia). Subsequently organic production increased rapidly during 11 523 120 BP (A2) and shallow lake was filled in. This is supported by presence of macroremains of Carex vesiraria/rostrata, C. riparia, Menyanthes trifoliata. Salix, Betula and Pinus wood fragments were also recorded indicating presence of birch-pine forest with intermingle of a spruce. Fires, which were frequent during the end of the Last Glacial, are documented by the record of a large number of burned seeds and charcoal. Calcium carbonate accumulations of the lake marl originated at the beginning of the Younger Dryas (11 010 60 BP). Increased sand deposits (A4) indicate a change from meandering type of the river to the braided one. The end of the sand deposition might be linked with the Glacial/ Holocene transition phase. Local human impact (A5) is documented in the middle of the Holocene (6510 40 BP). HIGH-RESOLUTION RECONSTRUCTION OF CLIMATE AND ENVIRONMENTAL HISTORY DURING FUNNEL-BEAKER CULTURE TIME BASED ON ANNUALLY LAMINATED LAKE SEDIMENTS OF LAKE BELAU AND LAKE POGGENSEE (NORTHERN GERMANY) Jürgen Zahrer. University Kiel, Institute for Ecosystem Research, Germany E-mail address: [email protected]
Synchronous deposition patterns of varves of two lakes in northern Germany were used to reconstruct climate history during the Funnelbeaker culture in north central Europe (5200-6900 cal BP) based on microfacies analysis. The onset of agricultural land use in the catchment areas of these lakes has been detected, too. The dating and synchronisation of the sequences are carried out by radiocarbon dating, tephrochronology and the varve chronology. For climate reconstruction a group of comparative indicators was applied: 1.) thickness of annual layers and the seasonal sub-laminae. 2.) palaeolimnologic-paleoclimatic indicators: Diatoms (genera), Phacotus spec., Crysophytes, autochthonous carbonate precipitation, detrital reworked carbonates, organic and minerogenic input.
A phase of cooler climatic conditions from 6050-5850 cal BP was detected and might reflect the known climatic event of the northern hemisphere (Bond event 4). The high temporal resolution enabled a further zoning: Besides four phases characterised by cold conditions a short, warm and dry phase was detected. Simultaneously, enrichment in minerogenic components and charcoal, preceding the onset of distinct settlement indicators for centuries, might suggest slope instability caused by natural forest fires. The following millenium showed indication for warmer climatic