- Email: [email protected]
Human landscapes of the Late Last Glacial in the interior of the Iberian Peninsula
Abstracts / Quaternary International 279-280 (2012) 9–120
in the Florida Straits. In addition, the chronology standardized growth indices correlate with the gridded (HadSST1) sea surface temperatures for late spring (AMJ), particularly strongly in the low to medium frequency parts of the spectrum. This enables SST to be reconstructed; the reconstruction indicates a prolonged period of falling SSTs between AD 1239 and AD 1313. THE APPLICATION OF PROXY DATA FROM HIGH RESOLUTION MARINE ARCHIVES TO PALAEOCLIMATE MODELS Paul Butler. School of Ocean Sciences, Bangor University, United Kingdom E-mail address: [email protected]
Annually resolved and absolutely dated natural archives for the marine environment represent perhaps the newest and fastest growing field in high resolution palaeoclimate studies. Until very recently, the lack of such archives has constrained palaeoclimate modelling of the integrated climate system, with relatively well informed reconstructions of atmospheric climate allowing the terrestrial system to be modelled in some detail while the closely coupled (and equally important) marine system remains relatively oversimplified. Recent research has demonstrated that long (1,000-year +) chronologies can be constructed using annual increments in the shell of long-lived bivalve molluscs. At the same time, advances in geochemical techniques for the analysis of carbonate shell material are widening the range of marine environmental parameters that are available for investigation. Taken as a combined field (‘sclerochronology’) this research has considerable potential to drive the integration of a much more complete and realistic marine member into coupled palaeoclimate models. MID-HOLOCENE CLIMATE VARIABILITY IN NORTHERN GERMANY AND ADJACENT OCEANS Camille Butruille. CAU, Germany E-mail address: [email protected]
During the Mid-Holocene Neolithic societies in Northern Central Europe underwent fundamental economic and societal changes, assumed to be co-determined by climatic and related environmental changes. While pollen-based reconstructions suggest stable temperatures, marine alkenone records from Skagerrak suggest a strong cooling subsequent to a Holocene Thermal maximum (HTM), a conflict so far unsolved. In terms of short term climate variability, deepwater renewal in the Skagerrak is considered to be highly sensitive to decadal/multi-decadal climate variability (AMO, NAO). These questions are addressed through high-resolution records of Skagerrak hydrographic variables (deep Mg/Ca and stable isotopes of benthic foraminifer; Uk’37 surface temperatures). Climatic trends between 7000 and 4000 ys BP were reconstructed for two Skagerrak sites (IOW225514, lat.57.8380, long.8.7040, 420m water depth; and IOW225517, lat.57.6670, long.7.0910, 293m water depth). Short-term climate variability of the marine records is compared to lacustrine records of a warved lake in northern Germany (Lake Belau, lat.54.1006, long.10.2528) using XRF records. Sea surface temperatures on the long term cooled by 3 C since 5500 ys BP, while deep-water temperatures warmed by 2 C. At the same time, deepwater ventilation improved (benthic d13C), and salinity increased, reflecting more vigorous deepwater renewal. Most records show a pronounced shift at 5000-5500 ys BP, tentatively related to a reorganisation of the Skagerrak system, and a transition from warmer and moister to cooler and drier conditions. This shift is also reflected in lake Belau coinciding with increase of landuse activities by Neolithic societies. Time series analysis reveal that multidecadal climate variability was inherent to both lacustrine and marine records, and increased distinctly after 5000 ys BP. Accordingly, Mid Holocene changes in Neolithic landuse and societal occurred towards a background of marked climate instability. HUMAN LANDSCAPES OF THE LATE LAST GLACIAL IN THE INTERIOR OF THE IBERIAN PENINSULA Carmen Cacho. Museo Arqueológico Nacional, Spain E-mail address: [email protected]
77
The cronostratigraphic framework of the Magdalenian in the interior of the Iberian Peninsula currently covers the period 18930 - 17850 cal. BP of level III at Alejandre (Deza, Soria) and 13100 - 12820 cal. BP of level I at Peña de Estebanvela (Ayllón, Segovia). These dates incorporate times of strong climatic oscillations, beginning with very rigorous environmental conditions (stage GS2) and ending with a temperate climate (Allerod); over this period, extreme events such as H1 occurred. However, little information is available that would allow the environments through which human groups moved during the Late Last Glacial of the Iberian interior to be characterised. The la Peña de Estebanvela site is something of an exception in that the results of analyses allow the reconstruction of the surrounding environment, and provide information on how natural resources may have been used. The faunas represented at this site reflect its palaeoecological variety over time. Taphonomic analysis of recovered macromammals and lagomorphs shows that these animals were brought to the site, butchered and consumed. The available data on seasonality fix the occupation of levels I-III to the autumn. Certain types of wood were collected for use as firewood. Other elements found in the record (personal ornaments, portable art and raw material) provide evidence that the people that occupied the site travelled over a more extensive territory. HOLOCENE TEPHRA CONSTRAINTS ON THE TIMING OF MILLENNIALSCALE VARIABILITY IN THE SUBPOLAR NORTH ATLANTIC Alix Gayle Cage. Keele University, United Kingdom E-mail address: [email protected]
The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the modulation of European climate and the westerly location of Scotland on the European Atlantic seaboard results in a strong regional relationship between North Atlantic driven weather systems and marine climate. High-resolution (1-4 yrs.cm-1) marine sedimentary archives of environmental change from the fjord settings of Scotland have shown that these marginal coastal environments are well-placed to capture millennial-scale climate variability throughout the Holocene (Cage & Austin, 2010). Recent tephrochronological advancements in microtephra analyses have allowed us to systematically search for Holocene tephra in sediment cores from Loch Sunart, NW Scotland, the first such tephra study from a British shelf-sea sediment core. The identification of established tephra isochrones will allow us to underpin the chronology of regional land-ocean interactions during the Holocene and critically test the timing of key climatic events in the North Atlantic region. Geochemical analyses on a basaltic shard peak from Loch Sunart core MD04-2831 suggests the tephra is from the basaltic phase of the AD 871 Landnám eruption (Iceland). This is the first record of Landnám tephra on the British-Irish mainland or shelf. Shards show physical properties which are characteristic of leaching processes and this susceptibility to chemical alteration under natural conditions may explain why basaltic particles from the AD 871 Landnám eruption have not yet been found in British terrestrial palaeoenvironmental records. THE VARIATION OF THE INDIAN MONSOON OVER THE PAST 245 KYR: SPELEOTHEM RECORDS FROM XIAOBAILONG CAVE, SOUTHWEST CHINA Yanjun Cai. Institute of Earth Environment, CAS, China E-mail address: [email protected]
An absolute-dated d18O record from Xiaobailong Cave, southwest China, completes a Chinese speleothem-based record of the Indian Monsoon (IM) over the past 245,000 years. The record is dominated by 23-kyr precessional cycles that are synchronous within dating errors with that of East Asian Monsoon (EAM) records from Sanbao Cave. The synchronicity of precessional cycles of both records with summer insolation at 65 N supports the idea that Asian monsoon respond dominantly and directly to changes in N-Hemisphere summer insolation on orbital timescales. The Xiaobailong record, similar to EAM speleothem records, demonstrates a remarkable resemblance to d 18O records from Greenland ice-core, suggesting that IM intensity changed in concert with Greenland temperature as well. This, in turn, suggests that the meridional thermal gradients in NHemisphere may be the main driving force behind the millennial-scale oscillations in intensities of both IM and EAM. However, there are also
in the Florida Straits. In addition, the chronology standardized growth indices correlate with the gridded (HadSST1) sea surface temperatures for late spring (AMJ), particularly strongly in the low to medium frequency parts of the spectrum. This enables SST to be reconstructed; the reconstruction indicates a prolonged period of falling SSTs between AD 1239 and AD 1313. THE APPLICATION OF PROXY DATA FROM HIGH RESOLUTION MARINE ARCHIVES TO PALAEOCLIMATE MODELS Paul Butler. School of Ocean Sciences, Bangor University, United Kingdom E-mail address: [email protected]
Annually resolved and absolutely dated natural archives for the marine environment represent perhaps the newest and fastest growing field in high resolution palaeoclimate studies. Until very recently, the lack of such archives has constrained palaeoclimate modelling of the integrated climate system, with relatively well informed reconstructions of atmospheric climate allowing the terrestrial system to be modelled in some detail while the closely coupled (and equally important) marine system remains relatively oversimplified. Recent research has demonstrated that long (1,000-year +) chronologies can be constructed using annual increments in the shell of long-lived bivalve molluscs. At the same time, advances in geochemical techniques for the analysis of carbonate shell material are widening the range of marine environmental parameters that are available for investigation. Taken as a combined field (‘sclerochronology’) this research has considerable potential to drive the integration of a much more complete and realistic marine member into coupled palaeoclimate models. MID-HOLOCENE CLIMATE VARIABILITY IN NORTHERN GERMANY AND ADJACENT OCEANS Camille Butruille. CAU, Germany E-mail address: [email protected]
During the Mid-Holocene Neolithic societies in Northern Central Europe underwent fundamental economic and societal changes, assumed to be co-determined by climatic and related environmental changes. While pollen-based reconstructions suggest stable temperatures, marine alkenone records from Skagerrak suggest a strong cooling subsequent to a Holocene Thermal maximum (HTM), a conflict so far unsolved. In terms of short term climate variability, deepwater renewal in the Skagerrak is considered to be highly sensitive to decadal/multi-decadal climate variability (AMO, NAO). These questions are addressed through high-resolution records of Skagerrak hydrographic variables (deep Mg/Ca and stable isotopes of benthic foraminifer; Uk’37 surface temperatures). Climatic trends between 7000 and 4000 ys BP were reconstructed for two Skagerrak sites (IOW225514, lat.57.8380, long.8.7040, 420m water depth; and IOW225517, lat.57.6670, long.7.0910, 293m water depth). Short-term climate variability of the marine records is compared to lacustrine records of a warved lake in northern Germany (Lake Belau, lat.54.1006, long.10.2528) using XRF records. Sea surface temperatures on the long term cooled by 3 C since 5500 ys BP, while deep-water temperatures warmed by 2 C. At the same time, deepwater ventilation improved (benthic d13C), and salinity increased, reflecting more vigorous deepwater renewal. Most records show a pronounced shift at 5000-5500 ys BP, tentatively related to a reorganisation of the Skagerrak system, and a transition from warmer and moister to cooler and drier conditions. This shift is also reflected in lake Belau coinciding with increase of landuse activities by Neolithic societies. Time series analysis reveal that multidecadal climate variability was inherent to both lacustrine and marine records, and increased distinctly after 5000 ys BP. Accordingly, Mid Holocene changes in Neolithic landuse and societal occurred towards a background of marked climate instability. HUMAN LANDSCAPES OF THE LATE LAST GLACIAL IN THE INTERIOR OF THE IBERIAN PENINSULA Carmen Cacho. Museo Arqueológico Nacional, Spain E-mail address: [email protected]
77
The cronostratigraphic framework of the Magdalenian in the interior of the Iberian Peninsula currently covers the period 18930 - 17850 cal. BP of level III at Alejandre (Deza, Soria) and 13100 - 12820 cal. BP of level I at Peña de Estebanvela (Ayllón, Segovia). These dates incorporate times of strong climatic oscillations, beginning with very rigorous environmental conditions (stage GS2) and ending with a temperate climate (Allerod); over this period, extreme events such as H1 occurred. However, little information is available that would allow the environments through which human groups moved during the Late Last Glacial of the Iberian interior to be characterised. The la Peña de Estebanvela site is something of an exception in that the results of analyses allow the reconstruction of the surrounding environment, and provide information on how natural resources may have been used. The faunas represented at this site reflect its palaeoecological variety over time. Taphonomic analysis of recovered macromammals and lagomorphs shows that these animals were brought to the site, butchered and consumed. The available data on seasonality fix the occupation of levels I-III to the autumn. Certain types of wood were collected for use as firewood. Other elements found in the record (personal ornaments, portable art and raw material) provide evidence that the people that occupied the site travelled over a more extensive territory. HOLOCENE TEPHRA CONSTRAINTS ON THE TIMING OF MILLENNIALSCALE VARIABILITY IN THE SUBPOLAR NORTH ATLANTIC Alix Gayle Cage. Keele University, United Kingdom E-mail address: [email protected]
The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the modulation of European climate and the westerly location of Scotland on the European Atlantic seaboard results in a strong regional relationship between North Atlantic driven weather systems and marine climate. High-resolution (1-4 yrs.cm-1) marine sedimentary archives of environmental change from the fjord settings of Scotland have shown that these marginal coastal environments are well-placed to capture millennial-scale climate variability throughout the Holocene (Cage & Austin, 2010). Recent tephrochronological advancements in microtephra analyses have allowed us to systematically search for Holocene tephra in sediment cores from Loch Sunart, NW Scotland, the first such tephra study from a British shelf-sea sediment core. The identification of established tephra isochrones will allow us to underpin the chronology of regional land-ocean interactions during the Holocene and critically test the timing of key climatic events in the North Atlantic region. Geochemical analyses on a basaltic shard peak from Loch Sunart core MD04-2831 suggests the tephra is from the basaltic phase of the AD 871 Landnám eruption (Iceland). This is the first record of Landnám tephra on the British-Irish mainland or shelf. Shards show physical properties which are characteristic of leaching processes and this susceptibility to chemical alteration under natural conditions may explain why basaltic particles from the AD 871 Landnám eruption have not yet been found in British terrestrial palaeoenvironmental records. THE VARIATION OF THE INDIAN MONSOON OVER THE PAST 245 KYR: SPELEOTHEM RECORDS FROM XIAOBAILONG CAVE, SOUTHWEST CHINA Yanjun Cai. Institute of Earth Environment, CAS, China E-mail address: [email protected]
An absolute-dated d18O record from Xiaobailong Cave, southwest China, completes a Chinese speleothem-based record of the Indian Monsoon (IM) over the past 245,000 years. The record is dominated by 23-kyr precessional cycles that are synchronous within dating errors with that of East Asian Monsoon (EAM) records from Sanbao Cave. The synchronicity of precessional cycles of both records with summer insolation at 65 N supports the idea that Asian monsoon respond dominantly and directly to changes in N-Hemisphere summer insolation on orbital timescales. The Xiaobailong record, similar to EAM speleothem records, demonstrates a remarkable resemblance to d 18O records from Greenland ice-core, suggesting that IM intensity changed in concert with Greenland temperature as well. This, in turn, suggests that the meridional thermal gradients in NHemisphere may be the main driving force behind the millennial-scale oscillations in intensities of both IM and EAM. However, there are also