The Quaternary Lancaster Sound trough‐mouth fan,NW Baffin Bay |
| |
| Authors: | Gang Li David JW Piper D Calvin Campbell |
| |
| Institution: | 1. MOE Key Laboratory of Coastal and Island Development, Nanjing University, Nanjing, China;2. Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada |
| |
| Abstract: | The development of the Lancaster Sound Trough Mouth Fan (TMF) and glacial history in Arctic Canada were studied using a high‐resolution seismic profile across the entire fan and two piston cores. Stacked tills separated by erosion surfaces on the shelf pass seaward through till deltas into thick transparent glacigenic debris flow (GDF) deposits on the slope, separated by thin, well‐stratified glaciomarine layers. An age model was built by ties to the Ocean Drilling Program Site 645. The deepest GDF on the seismic profile was indicative of the onset of shelf‐crossing glaciation in the Early Pleistocene. The transition of the growth of Lancaster Sound TMF from an aggradational sequence (unit M) to an aggradational–progradational sequence (unit F) occurred at the Middle Pleistocene transition in glacial cyclicity. In the most recent glacial cycle, GDF sheets were deposited during Heinrich events 4 and 2 according to the correlation of the main detrital carbonate beds in two piston cores. The outmost till wedge reflects the maximum advance of the grounding glacier, far seaward of previously proposed Last Glacial Maximum ice extent. Copyright © 2011 John Wiley & Sons, Ltd. |
| |
| Keywords: | glacigenic debris flow trough‐mouth fan stacking patterns chronology petrology sedimentology |
|
|
