T231 On the Edge—New Insights into Ice-Marginal Conditions I

Thursday, 29 October 2020
5:30 PM - 8:00 PM
Meeting Rooms

SURFICIAL MAPPING IN THE HOPEDALE REGION OF LABRADOR –A DYNAMIC, ICE-MARGINAL PALEOENVIRONMENT

Paper number: T231-4
Program: Technical Sessions
Time: 5:55 PM – 6:05 PM

Authors

Abstract

Deglaciation of the Laurentide Ice Sheet (LIS) in the Hopedale region of eastern Labrador has resulted in preferential erosion, deposition and further erosion of underlying bedrock and sediments. Rogen moraine and streamlined landforms northwest of the Harp Lake Intrusion and west of Sarah Lake (140 and 70 kilometers (km) from the present-day coastline) indicate ice-flow cessation, thinning and subsequent onset of fast-ice flow. River valleys leading from these regions to Flowers, Udjoktok and Big bays contain 90-150 meter thick ice-marginal sediment sequences that surround a 250-km2 area of preserved, locally streamlined disintegration moraine east of the Harp lake Intrusion, 45 km from the coastline. North and south of the moraine, U-shaped valleys are devoid of ice-marginal sedimentation. The localized distribution of ice-marginal sediments and the concentration of moraine and streamlined landforms at 140, 70 and 45 km west of the present day coastline suggests that deglaciation was not spatially or temporally uniform. Future work, including dating of these features from the coast to inland Labrador, would assist in establishing a timeline of deglaciation in this region, and would contribute to ongoing studies into the deglaciation of the LIS.

Geological Society of America Abstracts with Programs. Vol. 52, No. 6

doi: 10.1130/abs/2020AM-357743

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