Mineral resources of the Alvord Desert and East Alvord Wilderness Study Areas, Harney and Malheur counties, Oregon

Abstract

The Alvord Desert (OR-002-074) and East Alvord (OR-002-073A) Wilderness Study Areas encompass approximately 69,165 acres and 15,785 acres, respectively. In this report, the area(s) studied are referred to as the "wilderness study area(s)" or simply as "the study area(s);" any reference to the Alvord Desert or East Alvord Wilderness Study Area(s) refers only to that part of the wilderness study area(s) for which a mineral survey was requested by the U.S. Bureau of Land Management. The contiguous study areas, located along the eastern side of the Alvord Desert, Harney and Malheur Counties, Oreg., will be referred to as simply the study area unless otherwise noted. Geologic, geochemical, geophysical, and mineral surveys of the study areas were conducted by the U.S. Geological Survey and U.S. Bureau of Mines between 1986 and 1987 to evaluate the identified (known) mineral resources and to assess the mineral resource potential (undiscovered). There are no identified mineral resources, mining districts, mines, claims, oil , gas, or geothermal leases, or resource production in either of the study areas. Basalt and large quantities of dune sand that are present within the study areas are suitable for construction purposes but are not classified as an identified resource because they are not proximal to current or prospective markets. Geochemical and geophysical data suggest that the western part of the East Alvord Wilderness Study Area has a moderate potential for lowto medium-temperature geothermal resources. The remainder of the study area has a low potential for geothermal resources. In addition, the southwestern part has a low mineral resource potential for gold, silver, mercury, and boron in epithermal deposits. The northManuscript approved for publication, July 26, 1988. western part of the East Alvord Wilderness Study Area, near Mickey Springs, has a moderate resource potential for gold, silver, and mercury in epithermal deposits and a low resource potential for boron. The entire East Alvord Wilderness Study Area has a low potential for oil, gas, and uranium energy resources. A weak geochemical anomaly suggests a small area of low resource potential for gold and silver in epithermal deposits in the southern part of the East Alvord Wilderness Study Area as well. Geochemical and geophysical data suggest that the western part of the Alvord Desert Wilderness Study Area has a moderate mineral resource potential for lowto mediumtemperature geothermal resources. The remaining part has a low potential for lowto medium-temperature geothermal resources. The western part of the Alvord Desert Wilderness Study Area also has a low mineral resource potential for gold, silver, mercury, and boron in epithermal deposits. A geochemical anomaly suggests a small area of moderate resource potential for gold, silver, and mercury in epithermal deposits in the western part of the Alvord Desert Wilderness Study Area as well. The entire Alvord Desert Wilderness Study Area has a low potential for oil, gas, and uranium energy resources. Character and Setting The Alvord Desert and East Alvord Desert Wilderness Study Areas are situated in the transition zone between the Basin and Range and Columbia Plateau physiographic provinces. The Basin and Range province is an extensive semiarid to arid tract of subparallel, north-trending, en echelon mountain ranges and intervening valleys. The Columbia Plateau physiographic province is a high dissected plateau of Tertiary volcanic rocks (see appendixes for Geologic Time Chart). Mineral Resources of the Alvord Desert and East Alvord Wilderness Study Areas, Oregon B1 The study area is located in Harney and Malheur 84,950 acres in the two contiguous study areas along the Counties, Oreg., about 25 mi northeast of Fields (fig. 1). eastern edge of the Alvord Desert. In the rest of this report, The U.S. Bureau of Land Management requested studies on except where noted, the two areas will be referred to colAPPROXIMATE BOUNDARY OF EAST ALVORD WILDERNESS STUDY AREA (OR-002-073A) ., f Mickey Sprit (hot) STEENS-PUEBLO MINING DISTRICT