|Title||Surficial geology of the Glenlyon map area, Yukon Territory|
|Author||Ward, B C; Jackson, L E, Jr|
|Source||Geological Survey of Canada, Bulletin 559, 2000, 60 pages (4 sheets), https://doi.org/10.4095/211874 (Open Access)|
|Publisher||Natural Resources Canada|
|Maps||Publication contains 4 maps|
|Map Info.||surficial geology, landforms, lithology, 1:100,000|
|Media||paper; on-line; digital|
|Related||This publication contains the
|Area||Carmacks; Pelly River; Macmillan River; Yukon River; Glenlyon|
|Lat/Long WENS||-136.0000 -134.0000 63.0000 62.0000|
|Subjects||surficial 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|
|Illustrations||sketch maps; photographs; aerial photographs; stratigraphic columns|
|Released||2000 12 01; 2014 10 02; 2016 01 12|
|Abstract||Regional 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.