Geoscience Reference
In-Depth Information
Fig. 11.7
Evidence for overriding by cold-based glaciers in Arena Valley. The upper soil (above
the diabase ventifact in the center of the image) is of Taylor IV age (>1.0 Ma, <7.4 Ma) and the
buried soil is of Quartermain age (>11.3 Ma)
These data illustrate the effectiveness of Antarctic dry-based glaciers in
preserving underlying landforms and deposits, including soils. Moreover, the data
imply that Antarctic glaciers have been recycling clasts for the past ca. 15 Ma.
These fi ndings have important implications in selecting surface boulders for cos-
mogenic dating.
