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Geology topics

William Wallace Patton

Publications and source records attributed to William Wallace Patton.

At least 19 recordsLinked to original sources
USGS1984

The Alaskan Mineral Resource Assessment Program: Guide to information contained in the folio of geologic and mineral-resource maps of the Medfra quadrangle, Alaska

The Medfra quadrangle in west-central Alaska was investigated by a multidisciplinary team of geoscientists to assess its mineral resources. This Circular is intended to serve as a guide to a folio of 13 separate Open-File Reports covering various aspects of these investigations, including geology, bedrock and stream-sediment geochemistry, potassium-argon dating, Landsat imagery, mineral occurrences, aeromagnetic interpretation, and mineral-resource assessment. This Circular presents a complete reference list of these reports and a summary of the important results of each of the investigations.

Alaska↗
USGS1978

Contact-metasomatic magnetite deposit, Medfra Quadrangle, Alaska

A small contact-metasomatic magnetite deposit was discovered in the Medfra quadrangle, Alaska, in 1976. It occurs at the contact between a Cretaceous or early Tertiary quartz monzonite stock and Paleozoic limestone and dolomite. The ore is a magnetite-clinohumite-hematite rock that contains up to 60 volume percent magnetite and 76 weight percent total iron expressed as FeO. Computer modelling of data derived from a ground-level magnetometer survey yielded an estimate of the shape and volume of the deposit. The volume is grossly estimated at 11,600 3 m .

Alaska↗
USGS1975

Age and tectonic significance of volcanic rocks on St. Matthew Island, Bering Sea, Alaska

Reconnaissance investigations of the heretofore little known volcanic assemblage on St. Matthew Island provide significant information on the tectonic history of the Bering Sea shelf. St. Matthew Island is made up of approximately 500 m of subaerial calc-alkaline volcanic rocks ranging in composition from high-alumina basalt to rhyolite. Four K-Ar analyses of samples from this volcanic sequence give Late Cretaceous ages of 65-77 m.y., and intercalated carbonaceous tuff layers yield Cretaceous pollen assemblages. Along the northeast coast of St. Matthew Island the volcanic rocks are intruded by granodiorite that gives an early Tertiary K-Ar age of 61 m.y. Correlations with on-land geology in northeast Siberia and marine geophysical data from the western Bering Sea strongly suggest that St. Matthew Island represents a southeastward extension of the Okhotsk-Chukotsk belt, a Late Cretaceous and early Tertiary volcanic arc that borders the Pacific margin of Siberia for 3,000 km. The apparent continuation of this volcanic arc along the margin of the Bering shelf at least as far east as St. Matthew Island supports suggestions by Burk and by Scholl and others that in late Mesozoic time the Pacific plate margin coincided with the present-day Bering shelf margin and did not shift to the Aleutian trench until the end of Cretaceous or the beginning of Tertiary time. During the summer of 1971 the U.S. Geological Survey conducted a reconnaissance expedition to St. Matthew Island in the central Bering Sea aboard the Survey research vessel Don J. Miller II. The purpose of the expedition was to obtain basic geologic information on the age and lithologic character of the volcanic rocks on St. Matthew as part of a broad program of onshore and offshore investigations of the energy and mineral resources of the Bering Sea shelf. St. Matthew Island had not been mapped previously and available geologic information was confined to brief notes from early exploratory surveys of the Bering Sea region published more than 50 years ago (Dawson, 1894; Emerson, 1910). St. Matthew Island together with two small neighboring islands, Hall and Pinnacle, is situated 400 km west of mainland Alaska on the broad continental shelf that connects Alaska and Siberia (fig. 1). Although these islands have a combined area of only 350 2 km, they are important because they provide a rare subaerial exposure of the geology of the shelf and furnish new information on the tectonic history of the Bering Sea region. This report briefly describes the geology of the island and suggests how the island fits into the tectonic framework of the Bering Sea region.

Alaska↗
USGS1975

Geologic setting and chemical characteristics of hot springs in west-central Alaska

Numerous hot springs occur in a variety of geologic provinces in west-central Alaska. Granitic plutons are common to all the provinces, and the hot springs are spatially associated with the contacts of these plutons. Of 23 hot springs whose bedrock geology is known, all are within 4.8 km (3 mi) of a granitic pluton. The occurrence of hot springs, however, appears to be independent of the age, composition, or magmatic history of the pluton. Most of the analyzed hot springs appear to have chemical and isotopic compositions indicating that they were derived from deeply circulating meteoric water. About 25 percent of the analyzed hot springs show a distinct saline character with high concentrations of chloride, sodium, potassium, and calcium indicating either much more complex water-rock reactions than in the other hot springs or the addition of another type of water. Chemical geothermometers suggest subsurface temperatures in the general range of 70° to 160°C. If the hot spring waters have derived their heat solely from deep circulation, they must have reached depths of 2 to 5 km (6,000-15,000 ft), assuming geothermal gradients of 30° to 50°C/km. If a shallow igneous heat source exists in the area or if dilution or mixing has occurred, these depths may be shallower. The geologic and chemical data, although preliminary, suggest that most of the hot springs of west-central Alaska have relatively low subsurface temperatures and limited reservoir capacities in comparison with geothermal areas presently being utilized for electrical power generation. :The springs may, however, have some potential for limited power generation locally, if and when heat-exchange technology becomes available, as well as for space heating and agricultural uses.

Alaska↗
USGS1971

Cretaceous plutonic rocks of St. Lawrence Island, Alaska; a preliminary report

Reconnaissance mapping on St. Lawrence Island, Alaska has revealed seven epizonal granitic plutons of mid-Cretaceous age with a combined outcrop area of about 350 square miles. The plutonic rocks are dominantly quartz monzonite, but include minor amounts of granodiorite, monzonite, syenite, syenodiorite, and alaskite. The plutons are structurally and petrologically similar to and about the same age as plutons on the Chukotsky Peninsula, U.S.S.R. and in western Alaska. They suggest tectonic continuity between Siberia and Alaska since at least Cretaceous time. Several mineralized areas containing molybdenum, copper, lead, and zinc sulfides are associated with the plutonic bodies in the western part of the island.

Alaska↗