Quaternary geology of central Melville Island, Northwest Territories

Abstract

Moderately to completely weathered Devonian clastic rocks caver much of central Melville Island, including Dundas Peninsula. The principal Quaternary deposits are till and ice contact gravels, which occur in central and southeastern Dundas Peninsula. Deltaic and marine nearshore and beach sediments are scattered along lowland coasts. Continental ice sheets, dispersing from the south, reached their maximum limits on central Melville Island during at least three episodes; only the age of the last advance has been determined. The oldest and most extensive glaciation recognized covered at least southern Dundas Peninsula up to 300 m a.s.l. and deposited Dundas Till plus a major belt of ice contact deposits. During a subsequent glaciation, ice from Parry Channel overlapped the south-central coast of Dundas Peninsula up to 100 m a.s.l. and deposited Bolduc Till. This deposition may have occurred at the same time that ice entered Liddon Gulf from the south, depositing Liddon Till to 100 m a.s.l. on the outer gulf coast. At 11 700 ± 100 BP, all coasts were rising after crustal depression by ice assumed to have occupied Parry Channel and possibly covered the central Queen Elizabeth Islands. Maximum emergence on the south coast is at least 90 m; on all coasts farther north a prominent (and highest) water plane is recorded at about 55 m a.s.l. Subsequent to this initial emergence, ice from Parry Channel readvanced over, and retreated from, the south coast of Dundas Peninsula probably between 10 340 ± 150 and 9670 ± 150 BP, depositing Winter Harbour Till up to 120 m a.s.l. Because shoreline emergence was not significantly interrupted by this readvance, it is concluded that off shore this ice sheet was probably floating. Local ice caps existed at undetermined times on the uplands of Melville Island, north of Dundas Peninsula.

Arctic Ecological Classifications Derived from Vegetation Community and Satellite Spectral Data

“…The study area at CB is approximately 150 km 2 in size and is composed of two adjacent watersheds that drain into two separate lakes, and then south into Viscount Melville Sound. The area is underlain by steeply dipping sedimentary rocks of the Devonian Weatherall and Hecla Bay Formations and mantled with glacial and regressive early Holocene marine sediments [39]. Continuous permafrost with an active layer of 0.5-1 m covers the entire study area.…”

An Incidence of Multi-Year Sediment Storage on Channel Snowpack in the Canadian High Arctic

“…100 m above sea level. The area is underlain by steeply dipping sedimentary rocks of the Devonian Weatherall and Hecla Bay Formations and mantled with glacial and regressive early Holocene marine sediments (Hodgson et al, 1984). Continuous permafrost is present and forms an active layer ca.…”

Vegetation Community, Foliar Nitrogen, and Temperature Effects on Tundra CO2Exchange across a Soil Moisture Gradient

“…The northern study site at CB is approximately 150 km 2 in size and is comprised of two adjacent watersheds that drain into two separate lakes, and then south into Viscount Melville Sound. The area is underlain by steeply dipping sandstone and siltstone of the Devonian Weatherall, Griper Bay, and Hecla Bay Formations and overlain by late Quaternary glacial and marine sediments (Hodgson et al, 1984). The climate is cold throughout the year with a melt season extending from June through to August (Lamoureux and Lafrenière, 2009).…”