New Data on the Relief Development of the South Shetland Islands,Antarctica

Abstract

During several expeditions to the Antarctic Peninsula and the neighbouring islands, samples were collected from different sediments which contained datable materials or which were datable with new techniques. Thus it became possible to develop, together with our geomorphic field data, some new ideas on relief development at the rim of the Antarctic continent as well as on the glacial history of the area studied.

Planation surfaces in this area seem to be fairly old. For example, the prominent marine erosion surface on Fildes Peninsula, 35–45 m above mean sea level, is probably older than 85 000 years – older than the last interglacial period and the penultimate glaciation. All Holocene beaches, which are situated between 20 m and the present coastline, were formed during the last 6000 years.

Before 6000 BP the islands were still completely glaciated. The breakdown of the ice cover to nearly the present extent must have been extremely abrupt, taking no more than 1000 years (6000 to 5000 BP). Between 3000 and 1000 BP there were at least two re-advances. These advances were restricted to the prominent outlet glaciers, which followed pre-existing valleys.