Radiocarbon Dates from the Pleistocene Fossil Deposits of Samwel Cave, Shasta County, California, USA

Dates obtained from the collagen of 5 mammals from the fossil deposits of Samwel Cave, Shasta County, California, USA, show emplacement during the last glacial maximum. These dates support the assignment of the fauna to the late Pleistocene. The Samwel Cave deposits currently do not appear to be stratified.

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Absence of Last Glacial Maximum Records in Lowland Tropical Forests

Quaternary Research ◽

10.1006/qres.1997.1953 ◽

1998 ◽

Vol 49 (2) ◽

pp. 233-237 ◽

Cited By ~ 104

Author(s):

Marie-Pierre Ledru ◽

Jacques Bertaux ◽

Abdelfettah Sifeddine ◽

Kenitiro Suguio

Keyword(s):

South America ◽

Tropical Forests ◽

Last Glacial Maximum ◽

Sedimentation Rate ◽

Glacial Maximum ◽

Radiocarbon Dates ◽

Last Glacial ◽

The Last Glacial Maximum ◽

Pollen Records ◽

The Last Glacial

Environmental conditions of the lowland tropical forests during the last glacial maximum (LGM) between ca 20,000 and 18,000 14C yr B.P., are reevaluated in terms of dating control and lithology analyzed in seven pollen records from South America. The reevaluation shows that probably in none of the published records are LGM sediments present or abundant. This conclusion is based on the occurrence of abrupt lithologic changes coupled with changes in sedimentation rate interpolated from radiocarbon dates. These findings suggest that the LGM was represented probably by a hiatus of several thousand years, indicative of drier climates than before or after.

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Comparing a new paleomap of European loess landscapes to an atmospheric dust circulation model

10.5194/egusphere-egu21-4345 ◽

2021 ◽

Author(s):

Janina J. (Bösken) Nett ◽

Frank Lehmkuhl ◽

Erik J. Schaffernicht ◽

Stephan Pötter ◽

Philipp Schulte ◽

...

Keyword(s):

Last Glacial Maximum ◽

Late Pleistocene ◽

Circulation Model ◽

Glacial Maximum ◽

Source Areas ◽

Last Glacial ◽

Potential Source ◽

Aeolian Sediments ◽

The Last Glacial Maximum ◽

The Last Glacial

Loess is an important archive of environmental change covering approximately 10% of the Earth&#8217;s terrestrial surface. Numerous studies have analyzed loess deposits and in particular loess-paleosol sequences. To analyze these sequences, it is important to know the spatial distribution of aeolian sediments, their location relative to potential source areas, and the geomorphology of the sink area. We investigated these aspects by compiling a new map of aeolian sediments in Europe using highly resolved geodata from 27 countries (Lehmkuhl et al., in press). To determine the most relevant factors for the European loess distribution, we further mapped potential source areas and divided the map into different facies domains. We analyzed the geomorphological and paleoenvironmental effects on the deposition and preservation of Late Pleistocene loess. Finally, the geodata-based results were compared with results obtained from high-resolved regional numerical climate-dust experiments for the Last Glacial Maximum (LGM) in Europe, which were performed with the LGM-adapted Weather Research and Forecasting model coupled with Chemistry (WRF-Chem-LGM; Schaffernicht et al., 2020). &#160;Complementing the mapping-based findings with the WRF-Chem-LGM experiments results in an improved understanding of the Late Pleistocene loess landscape in Europe.&#160;References:Lehmkuhl, F., Nett, J.J., P&#246;tter, S., Schulte, P., Sprafke, T., Jary, Z., Antoine, P., Wacha, L., Wolf, D., Zerboni, A., Ho&#353;ek, J., Markovi&#263;, S.B., Obreht, I., S&#252;megi, P., Veres, D., Zeeden, C., Boemke, B., Schaubert, V., Viehweger, J., Hambach, U. (in press). Loess landscapes of Europe &#8211; Mapping, geomorphology, and zonal differentiation. Earth-Science Reviews. Doi: https://doi.org/10.1016/j.earscirev.2020.103496Schaffernicht, E.J., Ludwig, P., Shao, Y., 2020. Linkage between dust cycle and loess of the last Glacial Maximum in Europe. Atmospheric Chemistry and Physics 20, 4969&#8211;4986. Doi:10.5194/acp-20-4969-2020.

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Late Pleistocene hares of the Japanese archipelago: Paleobiogeographic implication at the Last Glacial Maximum

International Journal of Osteoarchaeology ◽

10.1002/oa.2645 ◽

2018 ◽

Vol 28 (2) ◽

pp. 179-187 ◽

Cited By ~ 2

Author(s):

Ryohei Sawaura ◽

Junmei Sawada ◽

Takao Sato ◽

Toshihiko Suzuki ◽

Keiichi Sasaki

Keyword(s):

Last Glacial Maximum ◽

Late Pleistocene ◽

Glacial Maximum ◽

Last Glacial ◽

Japanese Archipelago ◽

The Japanese Archipelago ◽

The Last Glacial Maximum ◽

The Last Glacial

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Wetter or colder during the Last Glacial Maximum? Revisiting the pluvial lake question in southwestern North America

Quaternary Research ◽

10.1016/j.yqres.2004.07.005 ◽

2004 ◽

Vol 62 (3) ◽

pp. 280-288 ◽

Cited By ~ 44

Author(s):

Kirsten M. Menking ◽

Roger Y. Anderson ◽

Nabil G. Shafike ◽

Kamran H. Syed ◽

Bruce D. Allen

Keyword(s):

Last Glacial Maximum ◽

Late Pleistocene ◽

Annual Runoff ◽

Glacial Maximum ◽

Water Runoff ◽

Last Glacial ◽

Pleistocene Climate ◽

Surface Water Runoff ◽

The Last Glacial Maximum ◽

The Last Glacial

Well-preserved shorelines in Estancia basin and a relatively simple hydrologic setting have prompted several inquiries into the basin's hydrologic balance for the purpose of estimating regional precipitation during the late Pleistocene. Estimates have ranged from 86% to 150% of modern, the disparity largely the result of assumptions about past temperatures. In this study, we use an array of models for surface-water runoff, groundwater flow, and lake energy balance to examine previously proposed scenarios for late Pleistocene climate. Constraints imposed by geologic evidence of past lake levels indicate that precipitation for the Last Glacial Maximum (LGM) may have doubled relative to modern values during brief episodes of colder and wetter climate and that annual runoff was as much as 15% of annual precipitation during these episodes.

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Exploring the phylogeography and population dynamics of the giant deer ( Megaloceros giganteus ) using Late Quaternary mitogenomes

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1864 ◽

2021 ◽

Vol 288 (1950) ◽

Author(s):

Alba Rey-Iglesia ◽

Adrian M. Lister ◽

Paula F. Campos ◽

Selina Brace ◽

Valeria Mattiangeli ◽

...

Keyword(s):

Genetic Diversity ◽

Last Glacial Maximum ◽

Late Pleistocene ◽

Late Quaternary ◽

Glacial Maximum ◽

Climatic Fluctuations ◽

The Holocene ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Late Quaternary climatic fluctuations in the Northern Hemisphere had drastic effects on large mammal species, leading to the extinction of a substantial number of them. The giant deer ( Megaloceros giganteus ) was one of the species that became extinct in the Holocene, around 7660 calendar years before present. In the Late Pleistocene, the species ranged from western Europe to central Asia. However, during the Holocene, its range contracted to eastern Europe and western Siberia, where the last populations of the species occurred. Here, we generated 35 Late Pleistocene and Holocene giant deer mitogenomes to explore the genetics of the demise of this iconic species. Bayesian phylogenetic analyses of the mitogenomes suggested five main clades for the species: three pre-Last Glacial Maximum clades that did not appear in the post-Last Glacial Maximum genetic pool, and two clades that showed continuity into the Holocene. Our study also identified a decrease in genetic diversity starting in Marine Isotope Stage 3 and accelerating during the Last Glacial Maximum. This reduction in genetic diversity during the Last Glacial Maximum, coupled with a major contraction of fossil occurrences, suggests that climate was a major driver in the dynamics of the giant deer.

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Could brown bears ( Ursus arctos ) have survived in Ireland during the Last Glacial Maximum?

Biology Letters ◽

10.1098/rsbl.2013.0281 ◽

2013 ◽

Vol 9 (4) ◽

pp. 20130281 ◽

Cited By ~ 6

Author(s):

Saoirse A. Leonard ◽

Claire L. Risley ◽

Samuel T. Turvey

Keyword(s):

Last Glacial Maximum ◽

Late Pleistocene ◽

Ice Sheet ◽

Brown Bear ◽

Glacial Maximum ◽

Source Population ◽

Brown Bears ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Brown bears are recorded from Ireland during both the Late Pleistocene and early–mid Holocene. Although most of the Irish landmass was covered by an ice sheet during the Last Glacial Maximum (LGM), Irish brown bears are known to have hybridized with polar bears during the Late Pleistocene, and it is suggested that the Irish brown bear population did not become extinct but instead persisted in situ through the LGM in a southwestern ice-free refugium. We use historical population modelling to demonstrate that brown bears are highly unlikely to have survived through the LGM in Ireland under any combination of life-history parameters shown by living bear populations, but instead would have rapidly become extinct following advance of the British–Irish ice sheet, and probably recolonized Ireland during the end-Pleistocene Woodgrange Interstadial from a closely related nearby source population. The time available for brown bear–polar bear hybridization was therefore restricted to narrow periods at the beginning or end of the LGM. Brown bears would have been extremely vulnerable to extinction in Quaternary habitat refugia and required areas substantially larger than southwestern Ireland to survive adverse glacial conditions.

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The Last Glacial Maximum in northern Baffin Bay

10.5194/egusphere-egu21-15295 ◽

2021 ◽

Author(s):

Karen Søby Özdemir ◽

Henrieka Detlef ◽

Linda Lambertucci ◽

Christof Pearce

Keyword(s):

Last Glacial Maximum ◽

Glacial Maximum ◽

Ice Shelf ◽

Radiocarbon Dates ◽

The Holocene ◽

Baffin Bay ◽

Last Glacial ◽

The Core ◽

The Last Glacial Maximum ◽

The Last Glacial

Little is known about climate and ocean conditions during the Last Glacial Maximum in Baffin Bay, Greenland. This is partly due to the dissolution of biogenic carbonates in the central Baffin Bay, preventing reliable 14C-chronologies. We present the results from a transect of gravity cores retrieved during the 2019 BIOS cruise on the HDMS Lauge Koch in the northern Baffin Bay. Core LK19-ST8-14G has been analyzed for grain size variations, sea-ice biomarkers, XRF, and color spectrophotometry. A preliminary chronology based on radiocarbon dates from foraminifera show that the bottom of the core is approximately 35.000 cal. years BP while the top sediments are of Late Holocene age. The sediment archive thus covers the full extent of the LGM and the last deglaciation. High-resolution photography and CT scans allowed the identification of distinctly different lithofacies in the sediment archive. The lower sections of the core are characterized by laminated mud with no IRD and absence of microfossils indicating a sub ice-shelf environment during the glacial period. The laminated sequence is interrupted by several coarser, detrital-carbonate (DC) rich layers which are interpreted as episodes of glacial retreat or ice-shelf collapse. The youngest of these DC layers immediately precedes the Holocene, which is represented by approximately 40 cm of bioturbated sediments with some IRD. This interpretation is supported by the concentrations of HBIs and sterols throughout the core, which indicate near perennial ice cover in the glacial northern Baffin Bay and more open water conditions during the Holocene.

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Sediment record of precipitation and changes in circulation in Bohol Sea area since the Last Glacial Maximum

10.5194/egusphere-egu2020-13383 ◽

2020 ◽

Author(s):

Sarahmae Buen ◽

Fernando Siringan ◽

Ronald Lloren

Keyword(s):

Sea Level ◽

Last Glacial Maximum ◽

Accumulation Rate ◽

The Philippines ◽

Glacial Maximum ◽

Radiocarbon Dates ◽

Last Glacial ◽

Sediment Input ◽

The Last Glacial Maximum ◽

The Last Glacial

Deep marine sediments may provide insights of past climate and oceanographic events. Knowledge of the past events can aid in scenario setting of future climate and their oceanographic consequences. A deep sea sediment core from the western side of Bohol Sea, a marginal sea located south of the Philippines, was used to reconstruct precipitation and identify the impacts of sea level rise on the circulation of Bohol Sea.&#160; Five radiocarbon dates from bulk organic matter provide age control spanning back to the Last Glacial Maximum. Sedimentological (lithics and carbonate fractions; bulk density; sedimentation rate and mass accumulation rate) and geochemical (Ti, Al, Zr, Ti/Al and Y/Ni) data were used to reconstruct the sediment input for the area. Sediment input was decreasing from 20-15ka, followed by a relatively stable trend until ~9ka. After ~9ka sediment input increased up until the most recent years. Sedimentation trend follows the average winter (DJF) insolation curve at 10oN. This signifies that the sediment input reflects the general changes in precipitation in the area. Lithics and carbonate contents reflect a shift in sediment source that could be attributed to the change in circulation in the basin as the sea level rose to overtop the Surigao Strait located at the northeastern side of the basin. Greater westward transport of suspended material from large rivers to the east would contribute to the sedimentation in the western part of Bohol Sea.

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