Mineral resources of the High Steens and Little Blitzen Gorge Wilderness Study Areas, Harney County, Oregon

Abstract

The contiguous High Steens (OR-002-085F) and Little Blitzen Gorge (OR-002-086F) Wilderness Study Areas are located along east-central Steens Mountain, Harney County, southeastern Oregon. At the request of the U.S. Bureau of Land Management, a total of 35,930 acres of the High Steens and 6,430 acres of the Little Blitzen Gorge Wilderness Study Areas were studied. In this report, the combined area studied is referred to simply as "the study area." Field work for this report was conducted between 1983 and 1985. About 500 claims and prospects have been located within and adjacent to the High Steens Wilderness Study Area, 52 of which are still active. No mining claims or prospects have been recorded within the Little Blitzen Gorge Wilderness Study Area. Perlite, with inferred marginal reserves totaling about 400,000 tons, is the only identified resource within the High Steens Wilderness Study Area. No identified resources are located in the Little Blitzen Gorge Wilderness Study Area. The potential for uranium resources is high in two areas along the southeast edge of the High Steens Wilderness Study Area; the potential for mercury resources is also high in one of these areas and the potential for gold resources is moderate in both areas. The potential for gold, mercury, and uranium resources in adjacent areas along the southeast and central-east edges of the High Steens Wilderness Study Area is moderate. The potential for resources of these commodities in an area along the northeast margin of the High Steens Wilderness Study Area is low. The western part of the High Steens Wilderness Study Area west of the Steens Mountain crest has unknown potential for these resources. The mineral resource potential for zeolites is low within a large area surrounding the southeast edge of the High Steens Wilderness Study Area; a low potential for perlite resources is assigned to the western part of this area. The potential for geothermal energy resources is low within a strip along the east margin of the High Steens Wilderness Study Area. The areas of known mineral resource potential and nearby mineral occurrences are related to a major basin-and-range fault zone existing along the base of the east escarpment of Steens Mountain. The entire High Steens Wilderness Study Area as well as the Little Blitzen Gorge Wilderness Study Area have a low potential for oil and gas resources. The Little Blitzen Gorge Wilderness Study Area has unknown potential for gold, mercury, and uranium resources. Character and Setting The High Steens (OR-002-085F) and Little Blitzen Gorge (OR-002-086F) Wilderness Study Areas are located along the east-central part of Steens Mountain in Harney County, Oreg., about 60 mi southsoutheast of Burns, Oreg. The 9,500-ft-high crest of Steens Mountain divides the combined study area into an eastern part characterized by a precipitous, eastfacing, 5,500-ft-high escarpment and a western part consisting of a gently west-dipping dissected plateau. The study area is underlain by a sequence of gently west-dipping Tertiary (see