Glacier-Rock Glacier Transition in the Southwest Yukon Territory, Canada

Abstract

In the southwest Yukon Territory rock glaciers of both the glacier debris system type and the talus type are common. In addition there are many examples of the transition between glaciers and the glacier-ice-cored type of feature. The glacier-ice-cored forms characteristically develop within or emanate from cirque basins where the formation of a complete debris cover of the glacier surface has been possible. Flow of these rock glaciers is due to periods of glacier advance with some secondary deformation of the ice under the debris cover after the retreat of the glacier. This secondary deformation accounts for movements measured at the present day. Comparisons are made among an ice-cored moraine system, a transitional form, and a large glacier-ice-cored rock glacier. The different flow lobes of the Grizzly Creek Rock Glacier indicate a number of periods of glacier activity in post Pleistocene times which may fit with the Denton and Karlén Holocene fluctuation model.