| Title | Retreat and stabilization of a marine-based ice margin along a high arctic fjord-cross-shelf trough system |
| |
| Author | Couette, P -O; Lajeunesse, P; Ghienne, J -F; Dorschel, B; Gebhardt, C; Hebbeln, D; Brouard, E |
| Source | Quaternary Science Reviews vol. 302, 107949, 2023 p. 1-26, https://doi.org/10.1016/j.quascirev.2022.107949  Open Access |
| Image |  |
| Year | 2023 |
| Alt Series | Natural Resources Canada, Contribution Series 20230017 |
| Publisher | Elsevier |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Province | Nunavut |
| NTS | 27E; 27F/01; 27F/02; 27F/07; 27F/08; 27F/09; 27F/10; 27F/15; 27F/16; 27G/01; 27G/02; 27G/07; 27G/08; 27G/09; 27G/10; 27G/15; 27G/16; 27H |
| Area | Baffin Island |
| Lat/Long WENS | -70.0000 -67.0000 71.0000 70.0000 |
| Subjects | sedimentology; deglaciation; Holocene; submarine features; marine sediments; marine sediment cores; climate; fiords; bathymetry; landforms; Laurentide Ice Sheet; Baffin Island; Arctic Archipelago;
Quaternary |
| Illustrations | location maps; tables; bathymetric profiles; profiles; lithologic logs; schematic representations |
| Released | 2023 01 17 |
| Abstract | Multibeam bathymetric and seismostratigraphic data collected in the Clyde fjord-cross-shelf trough system (eastern Baffin Island, Canadian Arctic Archipelago) display glacial landforms and depositional
assemblages that enable the identification of the maximal extent of the Laurentide Ice Sheet (LIS) margin and delineating the patterns and controls on its subsequent retreat. Additionally, 10 new sediment cores e from which seven radiocarbon ages
were acquired e allow the recognition of depositional processes. Results show that, during the Last Glacial Maximum, the LIS margin extended almost to the edge of the continental shelf. Early deglaciation of the trough was marked by an initial
ice-shelf collapse and rapid retreat of the ice stream, as evidenced by the absence of ice marginal landforms and the presence of extensive iceberg ploughmarks across a large portion of the outer trough. It was followed by a slow retreat and
successive stabilizations of the ice margin that led to the deposition of recessional moraines and grounding-zone wedges (GZWs). Deglaciation of the fjord in the early Holocene occurred in an episodic style, whereby rapid retreat was punctuated by
relatively long standstills that enabled major moraine formation. Long-term stabilizations of the ice margin in the Clyde fjord-cross-shelf trough system are interpreted to coincide with major climatic cooling events, such as the Younger Dryas and
early Holocene cold reversals. Ages derived from sediment cores and previous work suggest that higher retreat rates correspond with periods of significant global sea level rise, suggesting that oceanic forcing exerted a minor control on the
deglaciation. GZWs and large moraine ridges are observed at pinning points in the trough and fjord, indicating that the location of ice margin stabilizations was influenced by topography. The reconstruction of the deglaciation of the Clyde
fjord-cross-shelf trough system allows us to refine deglacial models for similar systems of northeastern Baffin Island, in particular beyond the coast and along the steeper section of the fjord where chronological gaps remained. |
| Summary | (Plain Language Summary, not published)
Bathymetry and subbottom data collected in the Clyde Inlet submarine valley system on the continental shelf of eastern Baffin Island to identifiy
submarine glacial landforms that are used to understand how far offshore glaciers extent during the last glaciation (~25,000 yrs ago) and how fast their subsequent melting occurred. Data show that, glaciers extended almost to the edge of the
continental shelf and that the initial deglaciation was marked the collapse of an ice-shelf and the rapid retreat of the glaciers to the mid-shelf. Subsequent deglaciation was slower and successive stabilizations of the ice margin led to the
deposition of moraines. Deglaciation of the fjord in the early Holocene occurred in an episodic style, whereby rapid retreat was punctuated by relatively long standstills that enabled major moraine formation. These stabilizations are interpreted to
coincide with major climatic cooling events, such as the Younger Dryas and early Holocene cold reversals. Ages derived from sediment cores and previous work suggest that higher retreat rates correspond with periods of significant global sea level
rise, suggesting that oceanic forcing exerted a minor control on the deglaciation. Moraine ridges are observed at pinning points in the trough and fjords, indicating that the location of ice margin stabilizations was influenced by topography. The
reconstruction of the deglaciation of the Clyde Inlet submarine valley system allows us to refine deglacial models for similar systems of northeastern Baffin Island, in particular beyond the coast and along the steeper section of the fjord where
chronological gaps remained. |
| GEOSCAN ID | 331834 |
|
|