Publications
Products (journal articles, reports, fact sheets) authored by current and past scientists are listed below. Please check the USGS Pubs Warehouse for other USGS publications.
Filter Total Items: 1826
Absence of magnetite microlites, geochemistry of magnetite veins and replacements in IOA deposits, SE Missouri, USA: Relations to intermediate intrusions
The paragenesis, textures, and chemical compositions of magnetite in two mafic to intermediate intrusions and four IOA deposits in SE Missouri were studied to discriminate between igneous and hydrothermal sources. In this study, we found that replacement magnetite with mineral inclusion-rich cores yields erroneously high Ti, Al, Si, Mg, and Mn contents as determined by EMP and LA-ICP-MS due to ru
Authors
Corey J. Meighan, Albert H. Hofstra, David Adams, Erin E. Marsh, Heather A. Lowers, Alan Koenig
Recognition and significance of Late Devonian fluvial, estuarine, and mixed siliciclastic-carbonate nearshore marine environments in the San Juan Mountains (southwestern Colorado, U.S.A.): Multiple incised valleys backfilled by lowstand and transgressive
The Upper Devonian Ignacio Formation (as stratigraphically revised) comprises a transgressive, tide-dominated estuarine depositional system in the San Juan Mountains (Colorado, USA). The unit backfills at least three bedrock paleovalleys (10–30 km wide and ≥42 m deep) with a consistent stratigraphy of tidally influenced fluvial, bayhead-delta, central estuarine-basin, mixed tidal-flat, and estuari
Authors
James E. Evans, Joshua T Maurer, Christopher S. Holm-Denoma
Occurrence and sources of radium in groundwater associated with oil fields in the southern San Joaquin Valley, California
Geochemical data from 40 water wells were used to examine the occurrence and sources of radium (Ra) in groundwater associated with three oil fields in California (Fruitvale, Lost Hills, South Belridge). 226Ra+228Ra activities (range=0.010-0.51 Bq/L) exceeded the 0.185 Bq/L drinking-water standard in 18% of the wells (not drinking-water wells). Radium activities were correlated with TDS concentrati
Authors
Peter B. McMahon, Avner Vengosh, Tracy Davis, Matthew K. Landon, Rebecca L. Tyne, Michael Wright, Justin T. Kulongoski, Andrew G. Hunt, Peter H. Barry, A.J. Kondash, Z. Wang, Christopher J. Ballentine
Magmatic-hydrothermal gold mineralization at the Lone Tree Mine, Battle Mountain district, Nevada
The Lone Tree deposit is located in the northern Battle Mountain mining district, Nevada. Prior to mine closure in 2006, Santa Fe Pacific Gold and Newmont produced 4.2 Moz of gold at an average grade of 2.06 g/t at Lone Tree, primarily from the N-S– to NNW-SSE–striking Wayne zone. The ore is located between the Roberts Mountain and Golconda thrusts in siliciclastic rocks of the Ordovician Valmy Fo
Authors
Elizabeth A. Holley, Justin Lowe, Craig A. Johnson, Michael Pribil
Crustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models
Several types of critical mineral-bearing ore deposits in the southern Midcontinent region of the U.S. are hosted in Mesoproterozoic igneous rocks largely concealed beneath Paleozoic cover. Discerning the architecture of igneous intrusions and volcanic centers in the crust is fundamental to understanding the geologic evolution of this vast region and its mineral resources. To advance the understan
Authors
Anne E. McCafferty, Jeffrey D. Phillips, Albert H. Hofstra, Warren C. Day
Thermotectonic history of the Kluane Ranges and evolution of the eastern Denali Fault Zone in southwestern Yukon, Canada
Exhumation and landscape evolution along strike‐slip fault systems reflect tectonic processes that accommodate and partition deformation in orogenic settings. We present 17 new apatite (U‐Th)/He (He), zircon He, apatite fission‐track (FT), and zircon FT dates from the eastern Denali fault zone (EDFZ) that bounds the Kluane Ranges in Yukon, Canada. The dates elucidate patterns of deformation along
Authors
Robert G. McDermott, Alexis K. Ault, Jonathan S. Caine, Stuart N. Thomson
The influence of foreland structures on hinterland cooling: evaluating the drivers of exhumation in the eastern Bhutan Himalaya
Understanding, and ideally quantifying, the relative roles of climatic and tectonic processes during orogenic exhumation is critical to resolving the dynamics of mountain building. However, vastly differing opinions regarding proposed drivers often complicate how thermochronometric ages are interpreted, particularly from the hinterland portions of thrust belts. Here we integrate three possible cro
Authors
Nadine McQuarrie, Paul R. Eizenhofer, Sean P. Long, Tobgay Tobgay, Todd A. Ehlers, Ann Blythe, Leah E. Morgan, Michelle Gilmore, Gregory M. Dering
The presence of antibiotic resistance genes in coastal soil and sediment samples from the eastern seaboard of the USA
Infections from antibiotic resistant microorganisms are considered to be one of the greatest global public health challenges that result in huge annual economic losses. While genes that impart resistance to antibiotics (AbR) existed long before the discovery and use of antibiotics, anthropogenic uses of antibiotics in agriculture, domesticated animals, and humans are known to influence the prevale
Authors
Dale W. Griffin, William Benzel, Shawn C. Fisher, Michael J. Focazio, Luke R. Iwanowicz, Keith A. Loftin, Timothy J. Reilly, Daniel Jones
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Eastern Ecological Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Kansas Water Science Center, New Jersey Water Science Center, New York Water Science Center, Pennsylvania Water Science Center, St. Petersburg Coastal and Marine Science Center, Utah Water Science Center
Sand Creek characterization study for Oncorhynchus clarkii virginalis (Rio Grande Cutthroat Trout), Great Sand Dunes National Park and Preserve, Colorado
The Oncorhynchus clarkii virginalis (Rio Grande cutthroat trout, RGCT) has undergone extensive declines in distribution and population. The RGCT is the southernmost distributed subspecies of cutthroat trout. Native to the Rio Grande Basin in Colorado and New Mexico, the subspecies is also found in the headwaters of the Pecos River and Canadian River basins in New Mexico. Currently, RGCT population
Authors
Ben N. Mcgee, Andrew S. Todd, Kevin K. Terry
Hydrocarbons in upland groundwater, Marcellus Shale Region, Northeastern Pennsylvania and Southern New York, USA
Water samples from 50 domestic wells located <1 km (proximal) and >1 km (distal) from shale-gas wells in upland areas of the Marcellus Shale region were analyzed for chemical, isotopic, and groundwater-age tracers. Uplands were targeted because natural mixing with brine and hydrocarbons from deep formations is less common in those areas compared to valleys. CH4-isotope, predrill CH4-concentration,
Authors
Peter B. McMahon, Bruce D. Lindsey, Matthew D. Conlon, Andrew G. Hunt, Kenneth Belitz, Bryant Jurgens, Brian A. Varela
By
Water Resources Mission Area, Energy Resources Program, National Water Quality Program, California Water Science Center, Central Energy Resources Science Center, Colorado Water Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, New England Water Science Center, Pennsylvania Water Science Center
Principles and history of luminescence dating
No abstract available.
Authors
Shannon A. Mahan, Regina DeWitt
Tourmaline boron and strontium isotope systematics reveal magmatic fluid pulses and external fluid influx in a giant iron oxide-apatite (IOA) deposit
Tourmaline is a common boron-bearing mineral in hydrothermal system and has been widely used as a mineral probe to reconstruct geological processes because of its broad range in composition and resistance to metasomatic alteration. The origin of Kiruna-type iron oxide-apatite (IOA) deposits, commonly linked to andesitic subvolcanic or volcanic rocks, is highly controversial. Constraints on the evo
Authors
Zhi-kun Su, Xinfu Zhao, Li-ping Zeng, Kui-dong Zhao, Albert H. Hofstra