The gold pan is ordinarily regarded as a tool for sampling placer deposits. Another and very important application is shown to be the sampling and study of decomposed bedrock, in regions where outcrops of hardrock are scarce or lacking. This technique was proposed and used by Derby, an American geologist who worked for many years in Brazil. The importance of this method has not been generally recognized, and the writer recalls it to the attention of geologists.An important application is shown to exist in the study of the decomposed bedrock, known as saprolite, that is so widespread in the Piedmont province of the southeastern United States. Using this technique, two projects have already been successfully completed in this region, and the success attained in both sets a new standard for geological exploration and mapping in areas where saprolite constitutes the dominant type of exposure.The technique of panning for heavy and semiheavy accessory minerals is described. Types of pans, factors in panning, the operation of panning, and the processing of concentrates in the field are briefly discussed. The gold pan, in the hands of an experienced operator, is shown to be a versatile and efficient field tool, which is completely independent of laboratory facilities.