Wrangel Island, off of eastern Siberia, was the last refuge of woolly mammoths before their final extinction. A population of mammoths became trapped on the island during rising sea levels at the end of the last glacial age. The isolation of the island from the mainland is interpreted by Arppe et al. from a distinct increase in the 87Sr/86Sr ratios of the mammoth skeletal remains, reflecting a change in the feeding area of the animals, from the vast plains of the continental self to the more mountainous area of present-day Wrangel Island.
Renewed glacial activity during the Antarctic cold reversal and persistence of cold conditions until 11.5 ka in southwestern Patagonia
P.I. Moreno et al., Dept. of Ecological Sciences and Institute of Ecology and Biodiversity, University of Chile, Santiago, Chile. Pages 375-378.
Resolving the timing, direction, and magnitude of paleoclimate changes in the southern middle-latitudes is a prerequisite for determining the mechanisms underlying abrupt and widespread climate changes between the hemispheres during the Last Glacial-Interglacial Transition (LGIT). Yet, this issue is still in debate, with previous studies producing apparently discordant findings. Here, Moreno et al. show evidence for a glacial re-advance and a cold episode between about 14.8 and 12.6 thousand years ago in southwest Patagonia (50 degrees south), contemporaneous with the Antarctic cold reversal. This was followed by ice recession under cold, but relatively milder, conditions until about 11.5 thousand years ago, when paleovegetation records indicate the onset of warm interglacial conditions. These findings differ from those reported in northern Patagonia (about 40 degrees south), where deteriorating conditions before 13.5 th
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