Geologic description
This occurrence consists of short, quartz veins, usually less than 6 inches thick, and numerous altered zones, about 2 feet thick. The altered zones transect metavolcanic rocks, schist, hornfels, slate, and marble. A few zones are localized along the margins of mafic dikes that cut the metamorphic rocks. The altered zones consist mainly of hydrous iron oxides, carbonate minerals, and quartz; minor pyrite, chalcopyrite, barite, and clay minerals are also present (MacKevett and others, 1971). MacKevett and others (1971) also report that the highest analytical metal values were from a sample consisting of sulfides, chiefly pyrite, replacing metavolcanic rocks, and from a sample of altered hornfels. These samples contained 1500 ppm zinc and anomalous silver, chromium, copper, molybdenum, and lead. The rocks in the vicinity of this occurrence consist of deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic units that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992). This occurrence is in a geologically complex area characterized by a variety of metamorphic rocks, small granitic plutons, and mafic dikes (MacKevett and others, 1971). |