Abstract: The Wrangell region of eastern Alaska represents a zone of extensive volcanism marked by intermittent pyroclastic activity during the late Holocene. The most recent and widely dispersed pyroclastic deposit in this area is the White River tephra, a distinct tephra-fall deposit covering 540 000 km 2 in Alaska, Yukon, and the Northwest Territories. This deposit is the product of two Plinian eruptions from Mount Churchill, preserved in two distinct lobes, created ca. 1887 years B.P. (northern lobe) and 1147 years B.P. (eastern lobe). The tephra consists of distal primary air-fall deposits and proximal, locally resedimented volcaniclastic deposits.

Distinctive layers such as the White River tephra provide important chronostratigraphic control and can be used to interpret the cultural and environmental impact of ancient large magnitude eruptions. The resedimentation of White River tephra has resulted in large-scale terraces, which flank the margins of Klutlan Glacier. Preliminary analysis of resedimented deposits demonstrates that the volcanic stratigraphy within individual terraces is complex and unique.

Authors: West, K.D. and Donaldson, J.A.

Keywords: volcanic stratigraphy, volcaniclastic deposits

NTS Mapsheet(s): 115F

Citation: West, K.D. and Donaldson, J.A., 2002. Resedimentation of the late Holocene White River tephra, Yukon Territory and Alaska. In: Yukon Exploration and Geology 2001, Emond, D.S., Weston, L.W., and Lewis, L.L. (eds.), Exploration and Geological Sciences Division, Yukon Region, Indian and Northern Affairs Canada, p. 239-247.

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