The object of a previous collaborative grant with Scripps Institution was to determine the production rates of 10Be and 26Al made by cosmic-ray interactions with quartz. We now plan to make use of this in situ production of cosmogenic radionuclides to study rates of erosion, extents of glaciation, rates of uplift, and in general, to determine histories of surface morphology. In addition to continuing measurements of 10Be and 26Al produced in quartz, we plan to study the 14C produced in the same samples-thus providing better control over the most recent exposure history (last -20 ka). We also plan to test the feasibility of measuring 41Ca in feldspars and soil samples. 41Ca's lifetime of -100 ka makes it appear ideal for studying surface development subsequent to the most recent period of glaciation, but complications arising from the fact that it is made from neutron capture, may make it too sensitive to water content and matrix effects to be useful as a chronometer. Finally, we would like to further improve our measurements capabilities for 26Al and 10Be, specifically by improving precision and by introducing automation into our measurement procedures.
