Palaeogeographical development of the Antarctic Peninsula during the late Cainozoic

Abstract

A geological research programme has been prepared as part of the activities of the Czech Republic to become a full member of the Antarctic Treaty Parties. In this paper, we review the present knowledge of the geological history of the Antarctic Peninsula (AP) and surrounding areas during the late Cainozoic. Particular attention is paid to James Ross Island, the site of the planned Czech Antarctic base. Glacial sediments older than Late Pleistocene are poorly preserved in and around the AP. The West Antarctic ice sheet is thought to have decayed during the last interglacial (OIS 5e), leaving only local centres of glaciation. Palaeogeographic development since the local Last Glacial Maximum (LGM; ~20-13.2 ka BP) can be reconstructed with a reasonable degree of confidence. Ice shelves surrounding the AP reached the outer margin of the continental shelf during the LGM. Marine sedimentation replaced till deposition on the outer and middle shelf 11 ka BP, but the inner shelf was not deglaciated before 6 ka BP. Continental glaciers receded mainly during the early Holocene, 9-5 ka BP. Glacier re-advance took place on the AP and adjoining continent at -5 ka BP, but was interrupted by the climatic warming which led to the Holocene climate optimum 4.2-3.0 ka ago. In view of the numerous disintegrations of AP ice shelves during the course of the Holocene, the present decay of some shelves does not represent an unusual event.