Affiliation:
1. Centre d’études nordiques and Département de géographie, Université Laval, Québec, Québec G1K 7P4
Abstract
This study presents a paleoenvironmental reconstruction of deglaciation dynamics and chronology, glaciomarine and postglacial sedimentation, as well as glacioisostatic recovery in the Rivière Nastapoka area, eastern Hudson Bay. Results indicate that the retreat of Québec-Labrador ice was mainly controlled by topography and was marked by four phases. Radiocarbon dates indicate that deglaciation began about 8.3 ka cal. BP and was characterized by a stillstand of the ice margin in the Nastapoka Hills that lead to the deposition of a drift belt in a high relative sea-level (Phase 1). After this stabilisation, the ice margin retreated rapidly eastward in a region of low relief and deposited a drape of silty clay in a falling relative sea-level (Phase 2). A second phase of stabilization of the ice margin lasted until at least 7.2 ka cal.BP on the higher shield peneplaine east of the limit of the Tyrrell Sea (Phase 3). This lead to the deposition of a belt of glaciofluvial deltas in a lower relative sea-level. Following this stillstand, the eastward retreat and subsequent ablation of the ice in central Québec-Labrador generated meltwater that transported large volumes of glacial sediments by fluvial processes and downcutting of fluvial terraces in previously deposited glaciofluvial and marine sediments (Phase 4). Glacioisostatic rebound reached 0.07 m/yr during the early phase of deglaciation and decreased to 0.04 m/yr between 6 and 5 ka cal. BP and 0.016 m/yr in the last 1000 years.
Reference54 articles.
1. Allard, M. and Seguin, M.K., 1985. La déglaciation d’une partie du versant hudsonien des rivières Nastapoka, Sheldrake et à l’Eau Claire. Géographie physique et Quaternaire, 39: 13-24.
2. ——— 1987. The Holocene evolution of permafrost near tree-line on the eastern coast of Hudson Bay (northern Québec). Canadian Journal of Earth Sciences, 24: 2206-2222.
3. Allard, M. and Tremblay, G., 1983a. La dynamique littorale des îles Manitounuk durant l’Holocène. Zeitschrift für Geomorphologie, N.F. Suppl., 47: 61-95.
4. ——— 1983b. Les processus d’érosion littorale périglaciaire de la région de Poste-de-la-Baleine et des îles Manitounuk sur la côte est de la mer d’Hudson, Canada. Zeitschrift für Geomorphologie, N.F. Suppl., 47: 27-60.
5. Andrews, J.T. and Falconer, G., 1969. Late glacial and post-glacial history and emergence of the Ottawa Islands, Hudson Bay, N.W.T.: Evidence on the deglaciation of Hudson Bay. Canadian Journal of Earth Sciences, 6: 1283-1276.
Cited by
17 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献