Warren Dickinson

Biography

A current project involves massive ground ice in the Antarctic Dry Valleys. Although the 8 Ma glacial ice in Beacon Valley has been hotly debated since Sugden and others reported it in 1995, similar occurrences have been found in Pearse and Victoria valleys. Such ice, which may be extremely old, is important because of the paleoenvironmental and paleobiological record it may contain. We are currently studying the geochemistry of this ice and attempting to date the surrounding sediments using optical luminescence and Beryllium 10. At Table Mountain in the Antarctic Dry Valleys, diagenetic minerals were found in cores of glacial sediments from the Sirius Group. This is significant because it is generally believed that the precipitation of diagenetic minerals requires large volumes of pore water at temperatures above 25oC. Chemical evidence suggests these minerals precipitated under freezing conditions from brine films, which can exist down to -50oC. This provides an Earth analogue for the precipitation of minerals on the surface of Mars. The Nelson Boulder Bank, a 13 km long boulder barrier is the largest of several boulder beaches in Tasman Bay, New Zealand. Numerous authors have concluded, from only visual observations that the Boulder Bank originated from a process of longshore drift. Our data suggests that the boulders could not have been emplaced by longshore drift in the low energy environment of Tasman Bay. The movement of boulders along a beach is a current topic of research, but it appears that the beaches are not formed by aggradation but by erosion of resistant bedrock and slightly modified by the present wave environment.

Research Interest

Sediment geochemistry, Antarctic permafrost, global mineral resources