The Quaternary Lancaster Sound Trough-mouth Fan, NW Baffin Bay
Gang Li1, David Piper2, and Calvin Campbell2
1MOE Key Laboratory of Coastal and Island Development, Nanjing University, Nanjing, China.
2Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, NS, Canada.
Glacial history in Arctic Canada was studied using a new-acquired high-resolution seismic profile and piston cores off Lancaster Trough in the northern Baffin Bay. The submarine fan off Lancaster Trough is a typical trough mouth fan consisting of stacked glacigenic debris flow (GDF) deposits confirmed by seismic profiles and piston cores. Recorded by the seismic profile, stacked tills are separated by erosion surfaces on the shelf and wedges of the till deltas and GDF were interbeded with glaciomarine deposits on the slope. The deepest GDF on the seismic profile was indicative of the onset of shelf-crossing glaciation in Arctic Canada in the early Pleistocene. The transition of the growth of Lancaster Sound TMF from an aggradational sequence to an aggradational-progradational sequence occurred at the Middle Pleistocene revolution in glacial cyclicity by ties to the ODP Site 645.
On the distal Lancaster Sound trough mouth fan, the surficial GDF lens recorded by Huntec profiles formed during Heinrich 4 and Heinrich 2 according to the correlation of the main detrital carbonate (DC) beds in two piston cores. On the shelf seven transgressive till wedges well shown on the Huntec profile record the glacial retreat process after the Last Glacial Maximum. The seaward extent of the LGM ice sheet margin in northern Baffin Bay may greatly exceed the extent proposed by Dyke et al. (2002).
AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.��������������������������������������