Deglaciation of the continental shelf off southern Troms, North Norway.

Abstract

Based on lithostratigraphical and seismic studies, four (possibly five) glacial events are recognized in Andfjorden. The two oldest, the I- and G-events are represented by basal tills. The continental ice sheet probably reached the shelf during deposition of these tills. Both the I- and G-events are older than c. 19,000 YBP and possibly younger than c. 36,000 YBP. The uncertain glacial event is represented by a questionable moraine ridge complex 20-25 km from the shelf edge. The Flesen event is represented by end moraines c. 50 km from the shelf edge; an age of 16,000-15,000 YBP is suggested. The D-event is identified as a glaciomarine sedimentary unit with high frequencies of ice-dropped clasts. During D-time the ice sheet crossed the sedimentary\/crystalline boundary in Malangsdjupet; in Andfjord it was probably situated just shoreward of this boundary. The age of the D-event is 14,000-13,000 YBP.