- Email: [email protected]
Climate, environment and human behaviour during the Middle Palaeolithic in eastern France
136
Abstracts / Quaternary International 279-280 (2012) 121–232
Paleoclimatic archives from the Marine Isotopic Stage 3 (MIS 3) depict some of the largest and fastest expressions of natural climatic variability. Large and rapid temperature fluctuations, the so-called DansgaardOeschger (DO) events, characterized this period with the alternation of cold stadials (GS) and warm interstadials (GI). Echoes of these major environmental excursions have been recognized worldwide (e.g. Voelker et al., 2002). We present here new data from three high-resolution marine sequences retrieved from the southern Norwegian Sea (core MD95-2010) and around Faeroes (cores MD95-2009; MD99-2281). Sea-surface temperatures (SST) and salinities, as well as sea-ice cover duration, have been quantified for MIS3 on the basis of an ecological transfer function derived from the analysis of dinocyst assemblages (e.g. de Vernal et al., 2001; 2005). These quantifications reveal major sea-surface palaeohydrological excursions, closely tied to the DO pace, but paradoxically document an atypical response of the Norwegian Sea environments. In fact, SST, as well as sea-ice cover duration data, converge to document warm GS and conversely, cold GI. These results, coherent in all the studied cores, highlight a possible decoupling of the low tropospheric temperatures between the Norwegian Sea region and its western counterpart over Greenland. However, our SST reconstructions displays a strong coherency in sign and magnitude with the central Greenland moisture source temperatures calculated from the GRIP deuterium-excess record (MassonDelmotte, et al., 2005; Jouzel et al., 2005; 2007). This observation questions the latitudinal and longitudinal reorganisations of the water cycle during MIS3 and previous interpretations of the origin of Greenland moisture during this period. TOWARDS A
10
BE PRODUCTION RATE FOR SCOTLAND
Derek Fabel. The University of Glasgow, United Kingdom E-mail address: [email protected]
The analytical precision of 10Be concentration measurements of are often better than w3% which means that landforms associated with glacial advance and retreat during abrupt climate changes such as the Younger Dryas should be resolvable. Unfortunately, global reference 10Be production rates are much less well constrained, introducing additional uncertainties of w9%. This means that the 1s full uncertainties of 10Be exposure ages from Younger Dryas landforms are typically w1000 yrs, not precise enough identify landforms formed at different stages of the Younger Dryas, or similar length climatic oscillations. In this study an attempt is made to overcome the limitations of the global reference production rate by determining a local 10Be production rate for Scotland. The calibration site includes the type section of the Loch Lomond Stadial (Greenland Stadial 1). Independent age control comes from 6 macro-fossil radiocarbon ages from an organic layer buried by a varved sequence of sediments. The varves record the existence of a glacially dammed lake that drained when the Loch Lomond Glacier retreated from its maximum position. 10Be concentrations measured in terminal moraine boulders marking this maximum glacial position will be discussed. CLIMATE, ENVIRONMENT AND HUMAN BEHAVIOUR DURING THE MIDDLE PALAEOLITHIC IN EASTERN FRANCE Magali Fabre. LAMPEA-Maison Méditerranéenne des Sciences de l'Ho, France E-mail address: [email protected]
Human subsistence and behaviour are closely related to climate and environment. Interpretation of zooarchaeological data should be done with a good knowledge of environment during the occupation. The cave “La Baume de Gigny” is located in the French Jura (eastern France). Its stratigraphic sequence covered a large timescale from MIS 6 to MIS 2. The middle complex, composed of 12 layers, constitute the reference for the Middle Palaeolithic of this region. Many of this layers delivered lithic tools and faunal remains. In order to understand human behaviour we undertake a pluridisciplinary study. The first analyse is based on the use of oxygen stable isotope from the phosphate of enamel from large mammal tooth in the way of past climate reconstruction. The second one is a zooarchaeological approach of the faunal assemblage. The geochemical data indicate a slowly but regularly increase of cold conditions from layer
XX to XV with more contrasted seasons that means a more continental climate. In a zooarchaeological point of view, we observed a decreased of the duration of cave occupation from a long occupation to a brief passage. “La Baume de Gigny”, with its well stratified sequence, shows a variation of the occupation of the cavities by Neandertal. When the climate become colder, the duration of occupation decreased with a more opportunistic subsistence. BIOLOGICAL INDICATORS OF RELATIVE SEA LEVEL CHANGE DURING THE LAST 2 KA ON THE ISLANDS OF VIS, RAVNIK AND BISEVO IN CROATIA Sanja Faivre. University of Zagreb, Croatia (Hrvatska) E-mail address: [email protected]
On the particularly exposed sites on rocky coasts of islands Vis, Ravnik and Bisevo in Croatia, biogenic littoral rims built by the coralline rhodophyte Lithophyllum lichenoides can be found. The presence of thick and welldeveloped Lithophyllum rims, considered to be precise (10 cm) sea-level indicator, points directly to the rising sea-level environment. Up to now five locations have been studied: 3 on the island of Vis, 1 on Ravnik and 1 on the island of Bisevo. Biogenic rims were mapped, measured and sampled for 14C dating. Three of the researched algal structures have two dominant levels: the upper one, 6 m long and 40 to 150 cm wide, and the lower one with a maximal extension of 40 cm. The surface of the lower level is 60 cm below the recent one. The thickness of each level at its most protruding part is around 15 cm. Today, on the relatively horizontal surface of the upper level algal rims the process of biodestruction prevails over bioconstruction. Living talli of Lithophyllum lichenoides were found only in small patches at the highest position on the horizontal surface of the rim and along its upper limit. Such a situation could clearly be connected to the recent acceleration of the sea-level rise as mentioned by Laborel et al., 1994. The prograding morphology of the algal rims points to the slowing of the sea-level rise starting at around 1 m below the MSL, when the algal rims began to develop. Based on the archaeological markers from 2300 100 yr BP till around 1900 100 yr BP the rate of relative sea level change was around 0.89 mm/yr (Faivre et al., in press) and then, according to the 14C dated algal samples it slowed down to 0.45 mm/yr from around 1450 yr BP till today. The obtained results have been compared not only with archaeological markers, e.g. submerged port remains of the ancient Issa harbour on the island of Vis, but also with geomorphological sea-level markers, as well as with other available data along the Croatian coast. THE NATURE AND TIMING OF MIS 3 INTERSTADIALS; NEW CONSTRAINTS FROM U-SERIES DATED SPELEOTHEMS FROM CRAG CAVE, S.W. IRELAND Adelheid Fankhauser. University College Dublin, Ireland E-mail address: [email protected]
The air temperature of shallow caves (<30 m depth) is similar to the mean annual air temperature (MAAT) at the surface. Speleothem deposition requires the presence of liquid water, and thus implies a cave air temperature above 0 C. Using this rationale, periods of speleothem deposition in Crag cave have been identified using U-series dates to constrain the timing of ice free conditions during the last glacial. U-Th ages indicate that while abundant speleothem deposition occurred in Crag cave during the Holocene, deposition also occurred during Marine Isotope Stage (MIS) 3. Preliminary results from two independent speleothems indicate that active deposition occurred episodically between 44.04 and 23.5 ka BP. In particular, periods of deposition, interrupted by visible hiatuses and/or changes in the speleothem depositional axis have been identified at (but not confined to) 44.0 0.6; 43.8 0.12; 41.95 0.04; 38.0 0.1; 34.6 0.2; 32.7 0.05; 27.9 0.04 and 23.5 0.03 ka BP. Importantly, these depositional periods in MIS 3 and at the beginning of MIS 2 coincide with Dansgaard-Oeschger (DO) events previously recognised in the Greenland ice cores and in speleothems from elsewhere. Measured d18O in the investigated MIS 3 speleothems is approximately 2& heavier than in Holocene reference material, which can be attributed
Abstracts / Quaternary International 279-280 (2012) 121–232
Paleoclimatic archives from the Marine Isotopic Stage 3 (MIS 3) depict some of the largest and fastest expressions of natural climatic variability. Large and rapid temperature fluctuations, the so-called DansgaardOeschger (DO) events, characterized this period with the alternation of cold stadials (GS) and warm interstadials (GI). Echoes of these major environmental excursions have been recognized worldwide (e.g. Voelker et al., 2002). We present here new data from three high-resolution marine sequences retrieved from the southern Norwegian Sea (core MD95-2010) and around Faeroes (cores MD95-2009; MD99-2281). Sea-surface temperatures (SST) and salinities, as well as sea-ice cover duration, have been quantified for MIS3 on the basis of an ecological transfer function derived from the analysis of dinocyst assemblages (e.g. de Vernal et al., 2001; 2005). These quantifications reveal major sea-surface palaeohydrological excursions, closely tied to the DO pace, but paradoxically document an atypical response of the Norwegian Sea environments. In fact, SST, as well as sea-ice cover duration data, converge to document warm GS and conversely, cold GI. These results, coherent in all the studied cores, highlight a possible decoupling of the low tropospheric temperatures between the Norwegian Sea region and its western counterpart over Greenland. However, our SST reconstructions displays a strong coherency in sign and magnitude with the central Greenland moisture source temperatures calculated from the GRIP deuterium-excess record (MassonDelmotte, et al., 2005; Jouzel et al., 2005; 2007). This observation questions the latitudinal and longitudinal reorganisations of the water cycle during MIS3 and previous interpretations of the origin of Greenland moisture during this period. TOWARDS A
10
BE PRODUCTION RATE FOR SCOTLAND
Derek Fabel. The University of Glasgow, United Kingdom E-mail address: [email protected]
The analytical precision of 10Be concentration measurements of are often better than w3% which means that landforms associated with glacial advance and retreat during abrupt climate changes such as the Younger Dryas should be resolvable. Unfortunately, global reference 10Be production rates are much less well constrained, introducing additional uncertainties of w9%. This means that the 1s full uncertainties of 10Be exposure ages from Younger Dryas landforms are typically w1000 yrs, not precise enough identify landforms formed at different stages of the Younger Dryas, or similar length climatic oscillations. In this study an attempt is made to overcome the limitations of the global reference production rate by determining a local 10Be production rate for Scotland. The calibration site includes the type section of the Loch Lomond Stadial (Greenland Stadial 1). Independent age control comes from 6 macro-fossil radiocarbon ages from an organic layer buried by a varved sequence of sediments. The varves record the existence of a glacially dammed lake that drained when the Loch Lomond Glacier retreated from its maximum position. 10Be concentrations measured in terminal moraine boulders marking this maximum glacial position will be discussed. CLIMATE, ENVIRONMENT AND HUMAN BEHAVIOUR DURING THE MIDDLE PALAEOLITHIC IN EASTERN FRANCE Magali Fabre. LAMPEA-Maison Méditerranéenne des Sciences de l'Ho, France E-mail address: [email protected]
Human subsistence and behaviour are closely related to climate and environment. Interpretation of zooarchaeological data should be done with a good knowledge of environment during the occupation. The cave “La Baume de Gigny” is located in the French Jura (eastern France). Its stratigraphic sequence covered a large timescale from MIS 6 to MIS 2. The middle complex, composed of 12 layers, constitute the reference for the Middle Palaeolithic of this region. Many of this layers delivered lithic tools and faunal remains. In order to understand human behaviour we undertake a pluridisciplinary study. The first analyse is based on the use of oxygen stable isotope from the phosphate of enamel from large mammal tooth in the way of past climate reconstruction. The second one is a zooarchaeological approach of the faunal assemblage. The geochemical data indicate a slowly but regularly increase of cold conditions from layer
XX to XV with more contrasted seasons that means a more continental climate. In a zooarchaeological point of view, we observed a decreased of the duration of cave occupation from a long occupation to a brief passage. “La Baume de Gigny”, with its well stratified sequence, shows a variation of the occupation of the cavities by Neandertal. When the climate become colder, the duration of occupation decreased with a more opportunistic subsistence. BIOLOGICAL INDICATORS OF RELATIVE SEA LEVEL CHANGE DURING THE LAST 2 KA ON THE ISLANDS OF VIS, RAVNIK AND BISEVO IN CROATIA Sanja Faivre. University of Zagreb, Croatia (Hrvatska) E-mail address: [email protected]
On the particularly exposed sites on rocky coasts of islands Vis, Ravnik and Bisevo in Croatia, biogenic littoral rims built by the coralline rhodophyte Lithophyllum lichenoides can be found. The presence of thick and welldeveloped Lithophyllum rims, considered to be precise (10 cm) sea-level indicator, points directly to the rising sea-level environment. Up to now five locations have been studied: 3 on the island of Vis, 1 on Ravnik and 1 on the island of Bisevo. Biogenic rims were mapped, measured and sampled for 14C dating. Three of the researched algal structures have two dominant levels: the upper one, 6 m long and 40 to 150 cm wide, and the lower one with a maximal extension of 40 cm. The surface of the lower level is 60 cm below the recent one. The thickness of each level at its most protruding part is around 15 cm. Today, on the relatively horizontal surface of the upper level algal rims the process of biodestruction prevails over bioconstruction. Living talli of Lithophyllum lichenoides were found only in small patches at the highest position on the horizontal surface of the rim and along its upper limit. Such a situation could clearly be connected to the recent acceleration of the sea-level rise as mentioned by Laborel et al., 1994. The prograding morphology of the algal rims points to the slowing of the sea-level rise starting at around 1 m below the MSL, when the algal rims began to develop. Based on the archaeological markers from 2300 100 yr BP till around 1900 100 yr BP the rate of relative sea level change was around 0.89 mm/yr (Faivre et al., in press) and then, according to the 14C dated algal samples it slowed down to 0.45 mm/yr from around 1450 yr BP till today. The obtained results have been compared not only with archaeological markers, e.g. submerged port remains of the ancient Issa harbour on the island of Vis, but also with geomorphological sea-level markers, as well as with other available data along the Croatian coast. THE NATURE AND TIMING OF MIS 3 INTERSTADIALS; NEW CONSTRAINTS FROM U-SERIES DATED SPELEOTHEMS FROM CRAG CAVE, S.W. IRELAND Adelheid Fankhauser. University College Dublin, Ireland E-mail address: [email protected]
The air temperature of shallow caves (<30 m depth) is similar to the mean annual air temperature (MAAT) at the surface. Speleothem deposition requires the presence of liquid water, and thus implies a cave air temperature above 0 C. Using this rationale, periods of speleothem deposition in Crag cave have been identified using U-series dates to constrain the timing of ice free conditions during the last glacial. U-Th ages indicate that while abundant speleothem deposition occurred in Crag cave during the Holocene, deposition also occurred during Marine Isotope Stage (MIS) 3. Preliminary results from two independent speleothems indicate that active deposition occurred episodically between 44.04 and 23.5 ka BP. In particular, periods of deposition, interrupted by visible hiatuses and/or changes in the speleothem depositional axis have been identified at (but not confined to) 44.0 0.6; 43.8 0.12; 41.95 0.04; 38.0 0.1; 34.6 0.2; 32.7 0.05; 27.9 0.04 and 23.5 0.03 ka BP. Importantly, these depositional periods in MIS 3 and at the beginning of MIS 2 coincide with Dansgaard-Oeschger (DO) events previously recognised in the Greenland ice cores and in speleothems from elsewhere. Measured d18O in the investigated MIS 3 speleothems is approximately 2& heavier than in Holocene reference material, which can be attributed