Geosciences and Environmental Change Science Center

Publications

Filter Total Items: 842
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Year Published: 2019

Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada

Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts of west-central Nevada. In the Tonopah mining district, volcanic rocks include the Mizpah...

du Bray, Edward A.; John, David A.; Colgan, Joseph P.; Vikre, Peter G.; Cosca, Michael A.; Morgan, Leah E.
du Bray, E.A., John, D.A., Colgan, J.P., Vikre, P.G., Cosca, M.A., and Morgan, L.E., 2019, Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield mining districts, Nevada: U.S. Geological Survey Scientific Investigations Report 2019–5024, 22 p., https://doi.gov/10.3133/sir20195024.

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Year Published: 2019

Guidance for assessing interregional ecoystem service flows

Ecosystem services (ES) assessments commonly focus on a specific biophysical region or nation and take its geographic borders as the system boundary. Most geographical regions are, however, not closed systems but are open and telecoupled with other regions through ES imports and exports, which are mediated by fluxes of matter, energy and...

Koellner, Thomas; Bonn, Aletta; Arnhold, Sebastian; Bagstad, Kenneth J.; Friedman, Dor; Guerra, Carlos; Kastner, Thomas; Kissinger, Meidad; Kleeman, Janina; Kuhlicke, Christian; Liu, Jianguo; Lopez-Hoffman, Laura; Marques, Alexandra; Martin-Lopez, Berta; Schulp, Catharina J. E.; Wolff, Sarah; Schröter, Matthias

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Year Published: 2019

Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada

The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples...

du Bray, Edward A.; John, David A.; Vikre, Peter G.; Colgan, Joseph P.; Cosca, Michael A.; Morgan, Leah E.; Fleck, Robert J.; Premo, Wayne R.; Holm-Denoma, Christopher S.
du Bray, E.A., John, D.A., Vikre, P.G., Colgan, J.P., Cosca, M.A., Morgan, L.E., Fleck, R.J., Premo, W.R., and Holm-Denoma, C.S., 2019, Petrographic, geochemical, and geochronologic data for Cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield mining districts, Nevada: U.S. Geological Survey Data Series 1099, 15 p., https://doi.org/10.3133/ds1099.

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Year Published: 2019

New geochemical evidence for the origin of North America's largest dune field, the Nebraska Sand Hills, central Great Plains, USA

The Nebraska Sand Hills region is the largest dune field in North America and has diverse aeolian landforms. It has been active during both the late Pleistocene and late Holocene. Despite decades of study, the source of sediment for this large sand sea is still controversial. Here we...

Muhs, Daniel R.; Budahn, James R.

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Year Published: 2019

The dependence of hydroclimate projections in snow‐dominated regions of the western United States on the choice of statistically downscaled climate data

We assess monthly temperature and precipitation data produced by four statistically based techniques that were used to downscale general circulation models (GCMs) in the Climate Model Intercomparison Program Phase 5 (CMIP5) (Taylor et al., 2012). We drive a simple water-balance model with the downscaled data to demonstrate the effect of the...

Alder, Jay R.; Hostetler, Steven W.

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Year Published: 2019

Calcrete uranium deposits in the Southern High Plains, USA

The Southern High Plains (SHP) is a new and emerging U.S. uranium province. Here, uranyl vanadates form deposits in Pliocene to Pleistocene sandstone, dolomite, and limestone. Fifteen calcrete uranium occurrences are identified; two of these, the Buzzard Draw and Sulfur Springs Draw deposits, have combined in-place resources estimated at about 4...

Hall, Susan; Van Gosen, Bradley S.; Paces, James B.; Zielinski, Robert A.

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Year Published: 2019

Pleistocene and Holocene landscape development of the South Platte River Corridor, Northeastern Colorado

This report provides a synthesis of geologic mapping and geochronologic research along the South Platte River between the town of Masters and the city of Fort Morgan, northeastern Colorado. This work was undertaken to better understand landscape development along this part of the river corridor. The focus is on times of rapid change within the...

Berry, Margaret E.; Slate, Janet L.; Taylor, Emily M.
Berry, M.E., Slate, J.L., and Taylor, E.M., 2019, Pleistocene and Holocene landscape development of the South Platte River corridor, northeastern Colorado: U.S. Geological Survey Scientific Investigations Report 2019–5020, 22 p., https://doi.org/10.3133/sir20195020.

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Year Published: 2019

A landscape model of variable social-ecological fire regimes

Fire regimes are now recognized as the product of social processes whereby fire on any landscape is the product of human-generated drivers: climate change, historical patterns of vegetation manipulation, invasive species, active fire suppression, ongoing fuel management efforts, prescribed burning, and accidental ignitions. We developed a new...

Scheller, Robert M; Kretchun, Alec; Hawbaker, Todd; Henne, Paul D.

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Year Published: 2019

A stratigraphic approach to inferring depositional ages from detrital geochronology data

With the increasing use of detrital geochronology data for provenance analyses, we have also developed new constraints on the age of otherwise undateable sedimentary deposits. Because a deposit can be no older than its youngest mineral constituent, the youngest defensible detrital mineral age defines the maximum depositional age of the sampled bed...

Johnstone, Samuel A.; Schwartz, Theresa M.; Holm-Denoma, Christopher S.

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Year Published: 2019

Bioavailable iron production in airborne mineral dust: Controls by chemical composition and solar flux

A large part of oceanic biological production is limited by the scarcity of dissolved iron. Mineral dust aerosol, processed under acidic atmospheric conditions, is the primary natural source of bioavailable iron to oceanic life. However, synergistic and antagonistic effects of non-Fe-containing minerals on atmospheric...

Hettiarachchi, Eshani; Reynolds, Richard L.; Goldstein, Harland L.; Moskowitz, Bruce M.; Rubasinghege, Gayan

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Year Published: 2019

North-south dipole in winter hydroclimate in the western United States during the last deglaciation

During the termination of the last glacial period the western U.S. experienced exceptionally wet conditions, driven by changes in location and strength of the mid-latitude winter storm track. The distribution of modern winter precipitation is frequently characterized by a north-south wet/dry dipole pattern, controlled by interaction of the storm...

Hudson, Adam M.; Hatchett, Benjamin J.; Quade, Jay; Boyle, Douglas P.; Bassett, Scott D.; Ali, Guleed; De los Santos, Marie G.

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Year Published: 2019

Evidence for non-steady-state carbon emissions from snow-scoured alpine tundra

High-latitude warming is capable of accelerating permafrost degradation and the decomposition of previously frozen carbon. The existence of an analogous high-altitude feedback, however, has yet to be directly evaluated. We address this knowledge gap by coupling a radiocarbon-based model to 7 years (2008–2014) of continuous eddy covariance data...

Knowles, John F.; Blanken, Peter D. ; Lawrence, Corey; Williams, Mark W.