Выпуск 22
Автор(ы):Hofstra A.H., Yigit O.
Издание:Journal Ore geology reviews, 2003 г., 24 стр.
Язык(и)Английский
Lithogeochemistry of Carlin-type gold mineralization in the Gold Bar district, Battle Mountain-Eureka trend, Nevada

The Gold Bar district contains five Carlin-type gold deposits and four resources for a combined gold endowment of 1.6 M oz [50 t]. The gold deposits are hosted in Devonian carbonate rocks below parautochthonous and allochthonous Paleozoic siliciclastic rocks emplaced during the Early Mississippian Antler orogeny. The district is in the Battle Mountain-Eureka trend, a long-lived structural feature that localized intrusions and ore deposits of different types and ages.

ТематикаПолезные ископаемые
Том 26, Выпуск 12
Автор(ы):Christopher D.Henry, David R. Boden
Издание:Journal Geology, 1998 г., 4 стр.
Язык(и)Русский
Eocene magmatism the heat source for Carlin-type gold deposits of northern Nevada

The origin of Carlin-type or sediment-hosted, disseminated gold deposits of the Great Basin, the major source of gold in the United States, is poorly understood. We propose that Eocene magmatism was the heat source that drove the hydrothermal systems that generated these deposits in the Carlin trend and Independence Mountains in northern Nevada. This interpretation is based on a strong spatial and temporal association of Eocene intrusive-volcanic centers with the gold deposits of this region. Our new work and published 40Ar/39Ar dates indicate that magmatism was particularly intense between 39 and 40 Ma throughout northeastern Nevada, especially in and around the area of gold deposits. Carlin-type deposits may have formed preferentially during Eocene magmatism because it was (1) more intense in the area than other magmatic episodes, (2) somehow compositionally distinct, or (3) accompanied by extension that promoted hydrothermal flow. However, large-scale extension does not appear to have been a factor in generating Carlin-type deposits.

ТематикаПолезные ископаемые
Автор(ы):Albert H. Hofstra, Jean S. Cline, John L. Muntean, Kenneth A. Hickey, Richard M. Tosdal
Издание:Economic geology, 2005 г., 34 стр.
Язык(и)Английский
Carlin-type gold deposits in Nevada: critical geologic characteristics and viable models

Carlin-type Au deposits in Nevada have huge Au endowments that have made the state, and the United States, one of the leading Au producers in the world. Forty years of mining and numerous studies have provided a detailed geologic picture of the deposits, yet a comprehensive and widely accepted genetic model remains elusive. The genesis of the deposits has been difficult to determine owing to difficulties in identifying and analyzing the fine-grained, volumetrically minor, and common ore and gangue minerals, and because of postore weathering and oxidation. In addition, other approximately contemporaneous precious metal deposits have overprinted, or are overprinted by, Carlin-type mineralization.

ТематикаПолезные ископаемые
Автор(ы):Calvin G. Barnes, Edward A. du Bray, Michael W.Ressel
Издание:U.S. Geological survey, Reston, 2007 г., 62 стр., ISBN: 1411317769
Язык(и)Английский
Geochemical database for intrusive rocks of north-central and northeast Nevada

Data presented in this report pertain to the igneous intrusions of north-central and northeast Nevada and were compiled as part of the Metallogeny of the Great Basin project conducted by the U.S. Geological Survey between 2001 and 2007. The geographic area addressed in this compilation is approximately bounded by lats 38.5° and 42°N., long 118.5° W., and the Nevada-Utah border (fig. 1). The area contains numerous large plutons and smaller stocks but also contains many small, shallowly emplaced intrusive bodies, including dikes, sills, and intrusive lava dome complexes. The age, composition, and geographic distribution of intrusions in north-central and northeast Nevada (hereafter, the study area) are summarized by du Bray and Crafford (2007). Intrusive igneous rocks, of multiple ages, are known to be major constituents of the geologic framework in the study area (Stewart and Carlson, 1978). Abundant middle to late Mesozoic and early to middle Cenozoic intrusions in the study area are probably byproducts of subduction-related processes, including back-arc magmatism, that prevailed along the west edge of the North American plate during this interval.

ТематикаГеохимия
МеткиГеохимия интрузивных пород, Невада
Автор(ы):David A.Davis, John L. Muntean, Jonathan G.Price, Lisa Shevenell, Richard Zehner
Издание:University of Nevada, Reno, 2011 г., 151 стр.
Язык(и)Английский
Nevada bureau of mines and geology special pubication MI-2010. The Nevada mineral industry 2010

This report highlights activities through 2010 in metals, industrial minerals, geothermal energy, and petroleum. Numerous graphs and charts are incorporated for rapid inspection of trends in production and price. The value of overall mineral and energy production in Nevada increased to an all-time high of $7.72 billion, up substantially from the previous high of $6.26 billion in 2008. Gold production experienced an increase to 5.3 million ounces in 2010, after more or less steadily decreasing from a high of 8.86 million ounces in 1998 to 5.0 million ounces in 2009. 2010 was the 22nd consecutive year with production in excess of 5.0 million ounces. Nevada led the nation in the production of gold, barite, and gypsum, and was the only state that produced magnesite, lithium, and the specialty clays, sepiolite and saponite. Other commodities mined and produced in Nevada in 2010, more or less in order of value, included copper, construction aggregate (sand, gravel, and crushed stone, including limestone and dolomite), silver, geothermal energy, petroleum, lime (produced from limestone and dolomite), cement (produced from limestone, clay, gypsum, and iron ore), silica (industrial sand), diatomite, clays, molybdenum, perlite, iron ore, dimension stone, salt, semiprecious gemstones (turquoise and opal), and mercury (as a byproduct of gold and silver processing). Locations of many of the sites mentioned in the text of this report are shown on NBMG map E-49, Nevada Active Mines and Energy Producers, which is available at www.nbmg.unr.edu/dox/e49.pdf.

ТематикаПолезные ископаемые, Экономика ГРР
Ленты новостей
1915.47