The Crandon massive sulfide deposit is covered by as much as 65 m of glacial drift. Soil gas was sampled at a depth of 0.5 m along several traverses over the deposit. Gases showing anomalies that correlate with the underlying deposit include CO 2 , CH 4 , and O 2 . CO 2 and CH 4 show positive anomalies with a background/anomaly ratio as high as 1 to 25, whereas O 2 shows negative anomalies. Oxidation of the sulfides with the production of sulfate is the probable chemical reaction producing some of the gas anomalies. The CH 4 anomalies may result from thermal cracking of hydrocarbon precursors. These results indicate that measurement of soil gases should provide a useful exploration tool in glacial terrain.