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Unfortunately, deposits containing such proxies are extremely rare and often difficult to date.
Here, we apply a unique dating approach to tundra deposits using concentrations of meteoric beryllium-10 (Be) adhered to paleolake sediments from the Friis Hills, central Dry Valleys.
Central to the dynamic/stable controversy is the timing of the onset of polar aridity, which limits substantial ice mass loss to only sublimation and is a key factor in determining long term EAIS mass balance.
The hyper-arid polar conditions of the Dry Valleys have protected inland sites from alteration due to weathering via precipitation or ice melt since the mid-Miocene.
A previously assumed Neoglacial advance is dated to 3.6 ± 0.3 ka and the CRN dates confirm a glacial advance ca. These results show that glaciations on the south side of Everest were not synchronous with the advance of Northern Hemisphere ice sheets, yet glaciations within the Himalaya, the world's highest mountain belt, were synchronous during the late Quaternary.
Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes.
Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 /- 700 beryllium-10 years and lasted 5900 years.
In the San Juan Mountains and the Front Range, glaciers may have begun their post-LLGM recession earlier, although early deglaciation is indicated by only a few ages on polished bedrock that potentially contains pre-LLGM CRN inheritance, and thus may be too old.
Regardless of the timing of the onset of deglaciation, the equilibrium-line rise associated with deglaciation was earlier and significantly larger in the San Juan Mountains than elsewhere in Colorado.