| Title | Reconstructing ice-margin retreat using delta morphostratigraphy |
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| Author | Dietrich, P; Ghienne, J F; Normandeau, A ; Lajeunessse, P |
| Source | Scientific Reports vol. 7, 16936, 2017, 10 pages, https://doi.org/10.1038/s41598-017-16763-x  Open Access |
| Image |  |
| Year | 2017 |
| Alt Series | Natural Resources Canada, Contribution Series 20170165 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Quebec |
| NTS | 12D; 12C; 12E; 12F; 12L; 12K; 12M; 12N; 22 |
| Area | Cote-Nord; Gulf of St-Lawrence |
| Lat/Long WENS | -73.0000 -60.0000 52.0000 48.0000 |
| Subjects | sedimentology; surficial geology/geomorphology; deltaic sediments; deltaic facies; deltaic deposits; deltas; ice movement directions; ice flow; ice retreat; ice sheets; glaciofluvial deposits; ice
contact deposits; sedimentation models; sedimentation dynamics; sediment reworking; Romaine; Aguanish; Magpie; Nastashquan; Sept-Iles; Manitou; Sainte-Marguerite; Pasteur; Walker; Godbout; Manicouagan; Outardes; Betsiamites; Escoumins;
Pentecote |
| Illustrations | location maps; schematic diagrams; tables |
| Released | 2017 12 05 |
| Abstract | The paleogeographic reconstruction of the successive inland positions of a retreating ice sheet is generally constrained by mapping moraines. However, deltaic complexes constructed by sedimentcharged
meltwater can also provide a record of the retreating ice-margin positions. Here, we examine a serie of ice-contact, ice-distal glaciofluvial and paraglacial depositional systems that developed
along the Québec North Shore (eastern Canada) in the
context of falling relative sea level during the northward retreat of the Laurentide Ice Sheet (LIS). Ice-contact depositional systems formed when the LIS was stillstanding along the Québec North Shore. Subsequent inland retreat of the ice margin
generated glacial meltwaters feeding sediment to glaciofluvial deltas, leading to their rapid progradation. The retreat of the ice margin from drainage basins was marked by the onset of paraglacial processes such as the shutdown of delta
progradation, severe fluvial entrenchment, and deposition of shallow-marine strata. Four end-member scenarios describe the spatial and stratigraphic distribution of these three depositional systems (ice-contact deposits, ice-distal glaciofluvial
deltas, and paraglacial
suites). They reflect both the inherited drainage basin physiography and the retreat pattern of the ice margin. Applied to twenty deltaic complexes, these end-members allowed us to refine the model of LISmargin retreat over
southeastern Québec. |
| Summary | (Plain Language Summary, not published)
Deltaic systems constructed when glacial meltwaters transported large volumes of sediment to the sea in a context of rapidly falling relative sea level
provides a record of the former positions of the retreating Laurentide ice margin. |
| GEOSCAN ID | 305605 |
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