Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16731
Mesozoic magmatism and base-metal mineralization in the Fortymile mining district, eastern Alaska — Initial results of petrographic, geochemical, and isotopic studies in the Mount Veta area Mesozoic magmatism and base-metal mineralization in the Fortymile mining district, eastern Alaska — Initial results of petrographic, geochemical, and isotopic studies in the Mount Veta area
We present here the initial results of a petrographic, geochemical, and isotopic study of Mesozoic intrusive rocks and spatially associated Zn-Pb-Ag-Cu-Au prospects in the Fortymile mining district in the southern Eagle quadrangle, Alaska. Analyzed samples include mineralized and unmineralized drill core from 2006 and 2007 exploration by Full Metal Minerals, USA, Inc., at the Little...
Authors
Cynthia Dusel-Bacon, John F. Slack, John N. Aleinikoff, James K. Mortensen
Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems
In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration...
Authors
Barnaby J. Watten, Michael Rust, John Colt
Minerals Yearbook, volume I, Metals and Minerals Minerals Yearbook, volume I, Metals and Minerals
The U.S. Geological Survey (USGS) Minerals Yearbook discusses the performance of the worldwide minerals and materials industries and provides background information to assist in interpreting that performance. Content of the individual Minerals Yearbook volumes follows:Volume I, Metals and Minerals, contains chapters about virtually all metallic and industrial mineral commodities...
Authors
Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho
Radiocarbon analyses of pollen, ostracodes, and total organic carbon (TOC) provide a reliable chronology for the sediments deposited in Bear Lake over the past 30,000 years. The differences in apparent age between TOC, pollen, and carbonate fractions are consistent and in accord with the origins of these fractions. Comparisons among different fractions indicate that pollen sample ages...
Authors
Steve M. Colman, Robert J. Rosenbauer, Darrell Kaufman, Walter E. Dean, John McGeehin
Interacción termal entre magmas graníticos laramídicos y rocas encajonantes mesoproterozoicas: Historia de enfriamiento de intrusivos de la sierrita blanca, NW Sonora Interacción termal entre magmas graníticos laramídicos y rocas encajonantes mesoproterozoicas: Historia de enfriamiento de intrusivos de la sierrita blanca, NW Sonora
A semi-quantitative thermochronological study, combining U-Pb and 40Ar/39Ar geochronology, has allowed assessment of the crystallization and cooling history of the Laramide Sierrita Blanca granite as well as the thermal effects resulting from the intrusion into the Mesoproterozoic host rocks (~1.1 Ga Murrieta granite). The U-Pb zircon age discrepancy between two samples of the Sierrita...
Authors
Monica A. Enriquez-Castillo, Alexander Iriondo, Gabriel Chavez-Cabello, Michael J. Kunk
Hydrologic conditions and a firm-yield assessment for J.B. Converse Lake, Mobile County, Alabama, 1991-2006 Hydrologic conditions and a firm-yield assessment for J.B. Converse Lake, Mobile County, Alabama, 1991-2006
J.B. Converse (Converse) Lake is the primary source of drinking water for the city of Mobile, Alabama. Concerns regarding the ability of the reservoir to meet current and future water demands during drought conditions have prompted this study. The 1991 through 2006 water years included a drought that occurred during 2000, and drought conditions currently (2007) are affecting the area. To...
Authors
Carl S. Carlson, Stacey A. Archfield
Mineral resource of the month: gold Mineral resource of the month: gold
No abstract available.
Authors
Micheal W. George
Mineral resource of the month: pumice and pumicite Mineral resource of the month: pumice and pumicite
The article offers information on pumice, an important commodity for the construction, horticulture and abrasives industries. The commodity is described as an extremely light, highly porous extrusive volcanic rock which was formed due to the rapid cooling of air-pocketed lava. It is noted that the characteristics of pumice make it as an ideal aggregate material in lightweight building...
Authors
Water Resources Division U.S. Geological Survey
Mineral resource of the month: thorium Mineral resource of the month: thorium
This article provides information on thorium. Thorium is a natural radioactive element that can be found with other minerals. It can be used to generate power, produce light and transmit energy. Thorium has a potential to be used as a nuclear fuel. This element was discovered by Swedish chemist and mineralogist Jóns Jakob Berzelius in 1828.
Authors
Water Resources Division U.S. Geological Survey
Mineral resource of the month: gold Mineral resource of the month: gold
The article presents information on the valuable mineral called gold. It states that early civilizations valued gold because of its scarcity, durability and characteristics yellow color. By the late 20th century, gold was used as an industrial metal because of its unique physicochemical properties. The U.S. has several productive deposits of gold, including placer, gold-quartz lode...
Authors
Micheal W. George
Mineral resource of the month: ferrous slag Mineral resource of the month: ferrous slag
The article offers information on mineral resource ferrous slag. Ferrous slag is produced through the addition of materials such as limestone and dolomite to blast and steel furnaces to remove impurities from iron ore and to lower the heat requirements for processes in iron and steel making. It is stated that the method of cooling is important for the market uses and value of ferrous...
Authors
Water Resources Division U.S. Geological Survey
Genetic structure in the Anaxyrus boreas species group (anura, Bufonidae): an evaluation of the Southern Rocky Mountain population Genetic structure in the Anaxyrus boreas species group (anura, Bufonidae): an evaluation of the Southern Rocky Mountain population
The Anaxyrus boreas species group is comprised of four species endemic to the western United States: A. boreas, A. canorus, A. exsul, and A. nelsoni. Disjunct populations of the widespread western toad Anaxyrus boreas from Colorado and southern Wyoming, the southern rocky mountain population (SRMP), were previously candidates for listing under the United States Endangered Species Act...
Authors
John F. Switzer, Robin L. Johnson, Barbara A. Lubinski, Tim L. King