Alsek River Streamcut

Fieldwork in Southeastern Alaska, 1979
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]

We visited several ridges where the stream cut through them, hoping to find layers of peat that could be tested for age by radiocarbon. As it happened, everywhere on these ridges was a thin skin of modern soil overlying clean sand and silt. These were not moraines, dirt piles left at the edge of former glaciers. They were more like beach berms, built up by winter storms and left behind for one reason or another (sedimentation, coseismic uplift, postglacial rebound . . . ) as the shoreline advanced seaward.

Start    Next >

_{(c) 2004 Andrew Alden, licensed to About.com, Inc.}