Table of Contents (cont'd) ILLUSTRATIONS Figure l. The HASL pressurized ionization chamber and y spectrometer set up for a typical measurement. Saratoga Springs, N.Y., 1963....29 Figure 2. Two typical field spectra obtained during Figure 3. Field spectrum obtained over freshly exposed late 1962....... sce eee eeeee cece ee eee ee ee 30 serpentine at asbestos mine near Copperopolis, California... .....c ee vccoee ce cect ewe twee ewes 31 Figure 4, Fresh serpentine exposure at asbestos mine near Copperopolis, California.............. 22232 iv