Cover Image Credits

The article by Spector and others (p. 637–676) describes geomorphic observations and cosmogenic-nuclide measurements on bedrock surfaces from three isolated nunatak groups in West Antarctica. The goals of the article are to (i) establish a chronology for landscape development in West Antarctica and (ii) quantify the long-term history of ice-thickness variations.

The cover photos show the position of an erosional trimline etched across the alpine landscape of the Pirrit Hills. The trimline separates smooth-crested ridges below from serrated ridges above, and it delineates a height above which has remained continuously exposed since the Miocene. The trimline is similar to a prominent and well-known trimline in the Ellsworth Mountains to the north (Denton and others, 1992), and we infer that they are, in fact, part of the same feature.