Quaternary Glaciomarine Sedimentation Interpreted from Seismic Surveys of Fiords on Baffin Island, N.W.T.

Abstract

Seismic reflection surveys using a compressed air source in nine fiords on Baffin Island provide information on the amounts of sediment deposited and the relation of sedimentation to events during late Quaternary glaciation. Five sedimentary facies can be recognised in the seismic records: (A) a basal facies of ice contact glacial sediment including moraines and deformed, stratified, glaciomarine sediment, (B) a lower glaciomarine facies of well-stratified sediment deposited in an ice-proximal environment, (C) a facies of acoustically transparent sediment deposited in a lower energy environment farther from sources of glacial sediment, (D) an upper, well-stratified facies similar to facies B and also interpreted as ice-proximal, and (E) a thin facies of modern sediment on top of the other materials. These facies are tentatively correlated with glacial events on eastern Baffin Island. Facies A and B are associated with the retreat of glaciers from the outer coast and continental shelf of Baffin Island during the early Foxe Period (>50,000 BP). Facies D is associated with the readvance of glaciers to form the moraines of the Baffinland drift during the Cockburn Substage of the Early Holocene. The intervening Facies C is associated with lower energy conditions and less sediment input in a long period between these events, and Facies E with the present environment in the fiords.

Key words: Baffin Island, fiords, sedimentology, continuous seismic profiling, Quaternary glaciation