The glacial geomorphology of West-Central Newfoundland; Halls Bay to the Topsails

Abstract

During the late Wisconsin glaciation, ice flow in west-central Newfoundland was to the north-northeast and northeast, sub-parallel to structural lineations. Constructional forms at this stage included drumlins, drumlinoid forms and ribbed moraine. -- The coast of Halls Bay was deglaciated about 12,000 B.P. in a relatively short period during which glaciomarine deltas were formed at Springdale, Dock Point, White Point, Barney's Brook, West Pond, South Brook and Sugarloaf; the latter three being remnants of a continuous terrace. Subsequent net isostatic and eustatic change positioned the deltas approximately 250 feet (75 meters) above present sea level. -- After the initial coastal stage of deglaciation, ice withdrew inland by stagnating in the valleys and lowlands leaving ridged ablation moraine and kettle topography. -- Ice receded in this manner to a plateau level 19 miles (30 kms.) from the coast, where a pause in retreat occurred. During this stage a series of recessional moraines was built and a zone of eskers formed near Barney's Brook and southeast of Sheffield Hill. Surficial crevasse fillings are also found within this zone. A final, topographically controlled flow into the Kitty's Brook - Chain Lakes valley system followed by stagnation, resulted in the fabrication of a series of recessional-ablation moraines. -- Last ice in the field area was situated to the southwest of Gaff Topsail and is evidenced by an area of hummocky, disintegration moraine.