Chemical Analyses and K-Ar Ages of Samples from 13 Drill Holes, Medicine Lake Volcano, California

This report presents chemical analyses and K-Ar ages obtained from drill hole samples studied in support of geologic mapping at Medicine Lake volcano (MLV), northern California. The holes were drilled by private companies exploring for geothermal energy at the volcano. Drill core and cuttings were later made available for study; core is stored at the Energy and Geoscience Institute (EGI) warehouse in Salt Lake City, Utah. Discussion of the significance of the chemical and age data will be presented elsewhere, although it is apparent from the cross-section and from Table 1 that a large percentage of MLV core consists of rocks with more than 63 percent SiO₂.