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TitleSurficial geology of the Glenlyon map area, Yukon Territory
AuthorWard, B C; Jackson, L E, Jr
SourceGeological Survey of Canada, Bulletin 559, 2000, 60 pages (4 sheets),
PublisherNatural Resources Canada
MapsPublication contains 4 maps
Map Info.surficial geology, landforms, lithology, 1:100,000
Mediapaper; on-line; digital
RelatedThis publication contains the following publications
File formatpdf
AreaCarmacks; Pelly River; Macmillan River; Yukon River; Glenlyon
Lat/Long WENS-136.0000 -134.0000 63.0000 62.0000
Subjectssurficial geology/geomorphology; stratigraphy; Holocene; Pleistocene; glaciation; glaciers; glacial stages; Wisconsinian glacial stage; landforms; glacial deposits; alluvial deposits; glaciolacustrine deposits; glaciofluvial deposits; stratigraphic analyses; stratigraphic correlations; tills; glacial history; fossils; Reid Glaciation; McConnell Glaciation; Pre-Reid Glaciation
Illustrationssketch maps; photographs; aerial photographs; stratigraphic columns
Released2000 12 01; 2014 10 02; 2016 01 12
AbstractRegional Quaternary mapping and stratigraphic and sedimentological studies were undertaken in the Glenlyon map area (NTS 105 L), with stratigraphic studies extending westward into the Carmacks map area (NTS 115-I). Surficial sediments were divided into 23 units, which range from Early Pleistocene to Holocene.
Evidence exists for at least three glaciations: pre-Reid (Early Pleistocene), Reid (Middle Pleistocene), and McConnell (Late Wisconsinan). Deposits of the Pre-Reid glaciation(s) have a very subdued surface morphology. The Reid Glaciation was less extensive and has better preserved landforms. Organic beds of Middle Wisconsinan age were identified, and insect macrofossils and pollen indicate forested conditions at 36 000-37 000 BP. Landforms and sediments of the McConnell Glaciation are well preserved, allowing for better reconstruction of conditions than the previous glaciations. The stratigraphic record suggests that rivers aggraded and an oscillation in the location of the ice front occurred during glacial advance. At glacial maximum, the Selwyn and Cassiar lobes of the Cordilleran Ice Sheet affected the area, with topography strongly controlling ice flow. Because of aridity, local cirques in the Glenlyon Range supported only small glaciers that did not contribute to the Selwyn Lobe.
At the end of the McConnell Glaciation, the retreat of glaciers was very rapid, with the ice sheet downwasting and stagnating in place. Many small lake basins developed in the Pelly River valley and large thicknesses of sediment were deposited on top of stagnant ice. Sediments were derived from the active ice margin, stagnant ice, marginal streams, and recently deglaciated valley sides.