The Gospel-Hump Wilderness lies in central Idaho. A mineral survey of the 206,500 acre area in Idaho County was conducted by the U.S. Geological Survey and the U.S. Bureau of Mines during 1980 to 1983. The study consisted of new geologic mapping, geochemical sampling of the wilderness and vicinity, geophysical surveying, and investigation of claim blocks in or near the wilderness. Fractures in the roof zone of plutons of the Idaho batholith host gold and silver deposits in mining districts that are contiguous with and included in the Gospel- Hump Wilderness. Subeconomic gold and silver resources are indicated and inferred at the War Eagle and Blue Jay mines (southeastern part of the area). Parts of the eastern half of the wilderness area, which are included in mining districts and which are along the trends of known mineralized fractures, have a high potential for gold and silver resources and moderate potential for copper, lead, zinc, and molybdenum resources in quartz fissure-veins. Other parts of the wilderness that have the same geologic setting have a moderate potential for gold and silver resources in undiscovered quartz veins that lie along the trend of or are parallel to known veins. The western third of the wilderness has a moderate potential for tungsten, silver, lead, copper, nickel, and possibly gold resources in skarn or metasomatic replacement deposits along thrust faults adjacent to carbonate units.

The Paxton Schist of Perry and Emerson (1903), referred to as the "Paxton Quartz Schist" by Emerson (1917), consists of medium-gray, thin- to medium-bedded, fine to coarse-grained schistose granulite, which weathers the same color or slightly darker with a brownish cast. It is pre- Ordovician and probably late Proterozoic in age. The Paxton is herein elevated to group status. The Paxton as revised excludes strata now assigned to the overlying Brimfield Group (Peper and others, 1975). The lower, fine-grained part of the Paxton is herein named the Dudley Formation, and the upper, interbedded, fine to coarse-grained part is referred to as the Southbridge Formation (Pease, 1972). An excellent reference section for the Paxton is present along the north- east side of the Quinebaug River southeast of Southbridge, Mass. The approximate thickness of exposed mapped width of the Paxton is 4,700 meters (m), of which the Dudley forms 1 ,000 m and the Southbridge 3,700 m. The Paxton conformably overlies the Oakdale Formation and underlies the Brimfield Group in its type area in central Massachusetts. It forms a northeast-trending belt extending from east-central Connecticut into southern Maine and probably into the central Maine coast. It is correlative with the Hebron Formation in eastern Connecticut, the upper part of the Berwick Formation in southern Maine, and the Rye Formation on the New Hampshire coast. A slight coarsening of the unit toward the northwest suggests a source in that direction.