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| Van Der Kaars, Sander; Miller, Gifford H.; Turney, Chris S. M.; Cook, Ellyn J.; Nürnberg, Dirk; Schönfeld, Joachim; Kershaw, A. Peter; Lehman, Scott J.. |
| Environmental histories that span the last full glacial cycle and are representative of regional change in Australia are scarce, hampering assessment of environmental change preceding and concurrent with human dispersal on the continent ca. 47,000 years ago. Here we present a continuous 150,000-year record offshore south-western Australia and identify the timing of two critical late Pleistocene events: wide-scale ecosystem change and regional megafaunal population collapse. We establish that substantial changes in vegetation and fire regime occurred similar to 70,000 years ago under a climate much drier than today. We record high levels of the dung fungus Sporormiella, a proxy for herbivore biomass, from 150,000 to 45,000 years ago, then a marked decline... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53192/55010.pdf |
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| Lindsay, Colin M.; Lehman, Scott J.; Marchitto, Thomas M.; Carriquiry, Jose D.; Ortiz, Joseph D.. |
| Previous studies have shown that radiocarbon activities (C-14) in the low-latitude, middepth Pacific and Indian Oceans were anomalously low during Heinrich Stadial 1 (HS1, similar to 17.8-14.6ka) and the Younger Dryas (YD, similar to 12.8-11.5ka), coincident with intervals of rising atmospheric CO2 concentration and declining atmospheric C-14. However, a full explanation of these events remains elusive due to sparse and sometimes conflicting data. Here we present new C-14 measurements on benthic and planktic foraminifera that, in combination with previously published measurements, enable us to reconstruct the C-14 depth gradient near Baja California. Vertical profiles were similar to present during the Last Glacial Maximum and BOlling/Allerod (14.6-12.8ka)... |
| Tipo: Text |
Palavras-chave: Radiocarbon; Deglaciation; Heinrich Stadial 1; Baja California; Benthic foraminifera. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00496/60797/64925.pdf |
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