Report issued by the Bureau of Mines over studies of mercury deposits in Nevada, and Oregon. History, physical features, and geology of the deposits are presented. This report includes maps, and illustrations.

Purpose: This study was conducted in order to assess the character and extent of Tertiary volcanic rocks and volcanic-derived sedimentary rocks as potential uranium host and (or) source rocks.

Introduction: This report presents engineering details, statistics, individual borehole histories, and geophysical logs of the eleven holes drilled in the McDermitt caldera project during the 1981 drilling program. General information is presented regarding specific problems, including weather and logistics. A separate geologic report is being prepared and will be available through the Bendix Field Engineering Corporation Technical Library in the near future.

From Introduction: "The Opalite quicksilver district includes two deposits with a considerable past production, one deposit with a small production, and one unproved prospect. These deposits are located along the circumference of a semicircular area that extends from a short distance west of McDermitt, Nev., for about 20 miles along the Oregon-Nevada State boundary. (See fig. 34). The area thus includes parts of Humboldt County, Nev., and Malheur County, Oreg.; almost the entire production has been derived from the portion in Oregon."

Supplementary data containing geophysical logs to accompany an engineering report on the McDermitt Caladera Drilling Project in Nevada and Oregon.