Late Weichselian glacial history and postglacial emergence of Phippsoya, Sjuoyane, northern Svalbard: a comparison of modelled and empirical estimates of a glacial-rebound hinge line

Field research on Phippsoya, the largest island in the Sjuoyane archipelago , defines the course and timing of postglacial emergence, documents past-gl acier movements, and reinterprets deglacial sedimentary sequences. Previous ly described tills were not identified in sections exposed along the northe ast short of Phippsoya, but instead sublittoral sediments with rock-fall co ncentrations derived from the adjacent slope. A glacio-isostatically higher sea level >40 ka deposited sublittoral sediment and is possibly correlativ e to a deglacial event in oxygen isotope stage 4 or 5 identified at other s ites on Svalbard. The postglacial marine limit is 22 +/- 1 m aht and occurs as an escarpment or washing limit into a stony drift. This drift contains granite and quartzite erratics from Nordaustlandet that indicate coverage b y a northward flowing ice sheet during the Late Weichselian. Datable materi al on the raised-beach sequence was rare and a C-14 age of c. 9.2 ka on an articulated Balanus balanus from 10m aht provides a minimum constraining ag e on the marine limit. A mild transgression occurred by 6.2 ka, with sea le vel falling close to present Levels by c. 5.0 ka. The zone of zero emergenc e (hinge line) lies 10 to 20 km north of Sjuoyane and is approximately coin cident with the last glacial maximum limit on the continental shelf. There is an approximately 75 to 100 km offset between observed and modelled zone of zero emergence, indicating a need to refine earth rheology-based ice-she et models.