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E. W. Tooker

Publications and source records attributed to E. W. Tooker.

11 recordsLinked to original sources
USGS1983

Correlation of metal occurrence and terrane attributes in the northwestern conterminous United States

The regional distribution patterns for 20 critical metals derived by an areal-pattern recognition technique leads me to conclude that metals are regularly distributed preferentially in the accreted and cratonic terranes studied in and surrounding the state of Oregon in the northwestern United States. The distribution patterns along distinctively different zones differ in these contrasting crusts across a concealed boundary that is established by strontium isotope data. Copper and gold appear to be abundant in both terranes; nickel, cobalt, chromium, and the platinum-group metals predominate in accreted terranes; lead, zinc, tin, and tungsten are concentrated locally along the boundary zone along the edge and in the interior of the cratonic terrane. The association of metals with accreted terranes and with restricted areas or lineaments in the craton further supports the metallogenetic hypothesis that metal materials are derived mainly from underlying ensialic and ensimatic crusts, and anticipates the possibility for remobilization of these materials along the same broad linear zones over geologic time.

California, Idaho, Montana, Nevada, Oregon, Utah, ↗
USGS1963

Economic geology of the Central City district, Gilpin County, Colorado

The Central City district, in Gilpin County, Colo., is on the east flank of the Front Range, about 30 miles west of Denver. The district is the most important mining camp in the Front Range mineral belt, and has yielded more than $100 million worth of gold, silver, uranium, and base-metal ores since 1859. Gold accounts for about 85 percent of the dollar value of the ore. In recent years mining activity has been slack but from 1950 to 1955 the search for uranium ores stimulated prospecting and development.

Colorado↗
USGS1954

Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these that deposited pitchblende.

Colorado↗