The early glaciation history of the Northern Hemisphere is a subject of controversy. Speculations about the onset of the glaciation of East Greenland varies from Plio/Pleistocene to middle Miocene. An ODP drill hole to study the age information of glacially influenced sediments does not exist on the North East Greenland shelf. So the beginning of the advances and retreats of the ice sheets is largely unknown.Seismic reflection data, gathered in 2003 along the North East Greenland margin in combination with analyses on the ODP site 913 provide a first age estimation of the sediments on the Greenland shelf. Major sedimentary elements of the Greenland shelf are thick Plio/Pleistocene deposits of more or less glacially related origin, which form widespread prograding sequences of variable extend. A comparison between shelf regions in the north and south of East Greenland show that prograding sequences are visible over a distance of about 25-80 km on the North East Greeland shelf and 5-30 km on the South East Greenland shelf. The occurrences of topsets within the shelf region along the East Greenland margin change from north to south. Topsets north of the Greenland Basin between 78°N to 81°N can be identified up to the shelf edge. However, data from South East Greenland show mostly an outer shelf with almost completely eroded topsets.Due to partially interpolation and extrapolation of age times we assume a starting of progradation in middle/early Miocene time on the North East Greenland shelf (77°N). A first age model for the Northern Greenland Basin will be introduced.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > MAR2-Palaeo Climate Mechanisms and Variability