COSMOGENIC NUCLIDE INSIGHTS INTO QUATERNARY LANDSCAPE EVOLUTION AND ICE SHEET HISTORY OF CENTRAL-WEST AND SOUTHWEST GREENLAND
Paired isotope calculations on all samples yielded differing total histories between the two research areas. Many surfaces in the Uummannaq region have minimum exposure durations up to ca. 300 kyr, but with no significant burial (within uncertainties). Most sampled surfaces in the Sukkertoppen region, however, yield complex exposure histories with minimum cumulative exposure durations up to ca. 100 kyr and minimum cumulative burial durations up to ca. 400 kyr, yielding minimum total histories up to 500 kyr. These findings suggest that parts of the Uummannaq landscape have been essentially continuously exposed throughout much of the late Quaternary, while high-altitude surfaces in the Sukkertoppen region were largely preserved beneath non-erosive, cold-based ice during the same period. Data from the Uummannaq region thus stand in contrast to other sites surrounding Baffin Bay. We hypothesize that surfaces in this region may have remained as nunataks above Last Glacial Maximum (LGM) Greenland ice due to large amounts of ice surface drawdown in the Uummannaq Ice Stream System (UISS).