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Robert Gordon Schmidt

Publications and source records attributed to Robert Gordon Schmidt.

7 recordsLinked to original sources
USGS1978

The Potential for Prophyry Copper-Molybdenum Deposits in the Eastern United States

Several significant porphyry-type deposits of Paleozoic age are known in New England and eastern Canada. Disseminated copper-molybdenum deposits of Paleozoic age are in the Southeastern United States, and copper is produced from porphyry-type deposits of both Precambrian and Paleozoic age in eastern Canada. Although these old deposits are surely less abundant than those in Cenozoic and Tertiary porphyry belts, the known Precrambrian and Paleozoic deposits in Eastern North America appear to be valid exploration targets. The difficult of 'prospecting in drift-covered and saprolite-mantled terrains suggests that all such deposits probably have not been discovered. Although such deposits are more costly to discover in this region than a massive sulfide deposit, the total amount of copper in even a medium-sized porphyry copper deposit is much greater than in most massive sulfide deposits. This report summarizes current knowledge of porphyry copper-molybdenum-type deposits in the Eastern United States and suggests more favorable areas for mineral exploration. Selected Canadian deposits are discussed because of their bearing on planning exploration in this country.

Professional Paper↗
USGS1952

Progress report on geologic study of the Crosby and Ironton area of the Cuyuna Range, Crow Wing County, Minnesota

The detailed geology of part of the Guyana manganiferous iron-ore district was mapped during the summer and autumn of 1951. The only exposures of bedrock in or near this area are in the open-pit and underground mines where two or more layers of iron-formation and associated elastic sediments have been deformed into a complex fold system and have been intruded by large dikes. The accompanying maps and sections show the distribution of the several rock types exposed, brief descriptions of these materials, and data on the geologic structure. For the most part this structural and lithologic information has been generalized from much more detailed maps prepared in the field on scales of 30, 40, or 50 feet equal to one inch.

Minnesota↗