This molybdenum-tungsten prospect is in a terrane composed mainly of Paleozoic sedimentary rocks. The prospect is east of a major fault that separates the Paleozoic strata from granitic rock of Mesozoic age. The fault is concealed by Brady Glacier and is inferred to control the course of Taylor Bay to the south (Brew and others, 1978). The deposit is of porphyry-type. Molybdenite and scheelite, with minor chalcopyrite, occur in the roof-zone of a Tertiary granodiorite stock that intrudes volcanic and sedimentary rocks (limestone) of Devonian age. The molybdenite and scheelite occur in quartz veins and as fracture coatings on joints in the intrusion. Molybdenum-bearing vein density measured by the U.S. Bureau of Mines (Kimball and others, 1978, p. C-253-C256) was about eight veins per 100 feet. The maximum observed vein thickness was 0.2 foot, with an average of about 0.08 foot. Mineralized veins and fractures strike east-northeast and dip from 25 to 76 degrees northwest. Selected vein samples contained as much as 2000 ppm molybdenum, 4917 ppm tungsten, 7 ppm silver, and 330 ppm copper. Iron-stained hornfels near the granitic stock contains as much as 200 ppm copper and 50 ppm tungsten.