Author : Koehler, L. Date : 2009. Title : Late Holocene glacial history of Manatee Valley, Upper Lillooet Provincial Park, Southern Coast Mountains, British Columbia. Publication : Unpublished MSc thesis. University of Victoria, Victoria, British Columbia. Issue : Page(s) :
This investigation uses dendrochronologic and radiometric techniques to infer the timing of glacier advance for four ice lobes that are drained by Manatee Creek in a remote valley located in the southern Coast Mountains, British Columbia. Dendroglaciologic evidence exposed by retreating glaciers provides evidence for increasing complexity in the Holocene glacial record, particularly for mid-late Holocene events. Since Holocene ice fronts periodically extended below treeline in the region, previous glacier advances overrode and buried forests beneath till deposits. The dendroglaciologic evidence presented here corroborates the record of glacier advances described for other southern British Columbia Coast Mountain glaciers and details ice front position at ca. 4270 14C yr BP, 3430 14C BP and 2350 14C yr BP. Well-preserved sequences of lateral, nested moraines were mapped and profiled to delineate the boundaries of Manatee and Oluk glaciers. Relative dates provided by lichenometry and dendrochronology were used as limiting dates for the deposition of 5-6 moraines during the late 14th, early 16th, early 18th, 19th, and early-20th Century. Reconstructions of Holocene glacial history offer insight into the regional, climatic regime and add to the discussion about pervasive, millennial-scale cycles.