Glacial marine sedimentation; Paleoclimatic significance
Glacial marine sedimentation from tidewater glaciers in the Canadian High Arctic
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Published:January 01, 1991
Northern Ellesmere Island is a polar desert with a mean annual coastal temperature of −18°C and annual precipitation of ca. 15 cm. Modern glaciers are predominantly frozen-bed, with sediment concentrated in debris-rich basal zones. This sediment cannot be entrained by the predominantly supraglacial stream systems, a condition accentuated where glaciers calve into the sea. Emergent early Holocene glacial marine sediments deposited within Clements Markham Inlet form a tripartite sequence of interbedded diamictons and silts; gravels and sands; and sands and silts. These lithofacies are interpreted as, respectively: debris flow and suspension settling sediments; subaquatic outwash fan channel and overbank sediments; and ice-proximal turbid plume suspension sediments. In contrast to the modern glacial setting, these lithofacies require the development and maintenance of a well-organized subglacial drainage network during deglaciation. The sediments do not provide a unique sedimentary facies model for high-latitude subpolar glaciers and are indistinguishable from temperate examples. This observation: (1) places severe constraints on our ability to distinguish glaciation style from deglacial sediments in marine settings; (2) suggests that low sedimentation rates in the Arctic Ocean are in part related to restricted glacial extents and effective sediment trapping in the fjords of the Canadian Arctic and Greenland; and (3) suggests that deglacial conditions at this high latitude were accompanied by warmer temperatures than present and may indicate that the early Holocene was as warm as, or warmer than, the mid-Holocene.
- Canada
- clastic sediments
- debris flows
- diamicton
- Ellesmere Island
- environment
- Franklin District Northwest Territories
- glacial sedimentation
- glaciers
- glaciomarine sedimentation
- gravel
- lithofacies
- marine sedimentation
- mass movements
- Northwest Territories
- Nunavut
- Queen Elizabeth Islands
- rainfall
- sand
- sedimentary petrology
- sedimentation
- sediments
- silt
- suspended materials
- Western Canada
- Clements Markham Inlet