Approach for quantifying rare Earth elements at low keV
Heather A. Lowers
2021, Microscopy and Microanalysis (27) 1864-1866
The challenges of analyzing bastnaesite (REECO3F) and hydroxylbastnaesite (REECO3OH) include beam sensitivity, quantification of light elements in a heavy element matrix, the presence of elements that cannot be analyzed with EPMA (H), and the use of x-ray lines whose physical constants are not well known. To overcome some of these...
Past abrupt changes, tipping points and cascading impacts in the Earth system
V. Brovkin, Edward J. Brook, J. Williams, S. Bathiany, T. Lenton, M. Barton, R. DeConto, J. Donges, A. Ganopolski, J. McManus, Summer K. Praetorius, A. de Vernal, A. Abe-Ouchi, H. Cheng, M Claussen, M. Crucifix, Virginia Iglesias, Darrell S. Kaufman, T. Kleinen, Fabrice Lambert, Sander van der Leeuw, Hannah Liddy, Marie-France Loutre, David McGee, Kira Rehfeld, Rachael H. Rhodes, Alistair W.R. Seddon, Lilian Vanderveken, Zicheng Yu
2021, Nature Geoscience (14) 550-558
The geological record shows that abrupt changes in the Earth system can occur on timescales short enough to challenge the capacity of human societies to adapt to environmental pressures. In many cases, abrupt changes arise from slow changes in one component of the Earth system that...
Belowground productivity varies by assessment technique, vegetation type, and nutrient availability in tidal freshwater forested wetlands transitioning to marsh
Andrew From, Ken Krauss, Gregory E. Noe, N. Cormier, Camille Stagg, Rebecca Moss, Julie L. Whitbeck
2021, PLoS ONE (16)
Wetlands along upper estuaries are characterized by dynamic transitions between forested and herbaceous communities (marsh) as salinity, hydroperiod, and nutrients change. The importance of belowground net primary productivity (BNPP) associated with fine and coarse root growth also changes but remains the dominant component of overall productivity in these important blue...
Occurrence and distribution of mercury in streams and reservoirs in the Triangle Area of North Carolina, July 2007–June 2009
Anna M. McKee, Sharon Fitzgerald, Mary J. Giorgino
2021, Scientific Investigations Report 2021-5027
During the time period 2001–2006, the U.S. Geological Survey reported mercury-concentration measurements that exceeded the North Carolina water-quality criterion (NCWQC) of 0.012 microgram per liter for total recoverable mercury in streams and reservoirs across the Triangle Area of North Carolina. Mercury data were sparse, however, generally consisting of only one...
Machine learning to identify geologic factors associated with production in geothermal fields: A case-study using 3D geologic data, Brady geothermal field, Nevada
Drew L. Siler, Jeff D. Pepin, Velimir V. Vesselinov, Maruti K. Mudunuru, Bulbul Ahmmed
2021, Geothermal Energy – Science, Society and Technology (9)
In this paper, we present an analysis using unsupervised machine learning (ML) to identify the key geologic factors that contribute to the geothermal production in Brady geothermal field. Brady is a hydrothermal system in northwestern Nevada that supports both electricity production and direct use of hydrothermal...
GIS-based identification of areas that have resource potential for lode gold in Alaska
Susan M. Karl, Douglas C. Kreiner, George N.D. Case, Keith A. Labay, Nora B. Shew, Matthew Granitto, Bronwen Wang, Eric D. Anderson
2021, Open-File Report 2021-1041
Several comprehensive, data-driven geographic information system (GIS) analyses were conducted to assess prospectivity for lode gold in Alaska. These analyses use available geospatial datasets of lithologic, geochemical, mineral occurrence, and geophysical data to build models for recognizing different types of gold deposits within physiographic units defined by stream drainage basins...
South Dakota and Landsat
U.S. Geological Survey
2021, Fact Sheet 2021-3035
Few States derive as much of their social and economic well-being from the land as South Dakota. Agriculture is the State’s primary industry. Hunting, fishing, tourism, mining, and hydroelectric power are also important economic and cultural drivers. Data from the U.S. Geological Survey Landsat program, archived at the U.S. Geological...
Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites
Jeffrey J. Marlow, Daniel Hoer, Sean Jungbluth, Linda Reynard, Amy Gartman, Marko S. Chavez, Mohamed Y. El-Naggar, Noreen Tuross, Victoria Orphan, Peter R. Girguis
2021, Proceedings of the National Academy of Sciences (PNAS) (118)
At marine methane seeps, vast quantities of methane move through the shallow subseafloor, where it is largely consumed by microbial communities. This process plays an important role in global methane dynamics, but we have yet to identify all of the methane sinks in the deep sea. Here, we conducted a...
Cyanotoxin occurrence in the United States: A 20 year retrospective
Jennifer L. Graham
2021, Lakeline (41) 8-11
Cyanobacterial blooms, and associated cyanotoxin occurrence, are a concern because of the potential harms posed to humans, wildlife, and aquatic ecosystem health. Evidence suggests the magnitude, frequency, and duration of cyanobacterial blooms are increasing, and these events represent a significant challenge to freshwaters and, increasingly, marine waters, worldwide. Cyanobacterial blooms...
A review of sand detachment in modern deep marine environments: Analogues for upslope stratigraphic traps
John W. Counts, Lawrence Amy, Aggeliki Georgiopoulou, Peter Haughton
2021, Marine and Petroleum Geology (132)
Isolated, detached sands provide opportunities for large-volume stratigraphic traps in many deepwater petroleum systems. Here we provide a review of the different types of sandbody detachments based on published data from the modern-day seafloor and recent (generally Quaternary-present), shallow-buried strata. Detachment mechanisms...
Development of soil radiocarbon profiles in a reactive transport framework
Jennifer Druhan, Corey Lawrence
2021, Geochimica et Cosmochimica Acta (306) 63-83
Today, there is a greater appreciation for the importance of the physical protection of carbon (C) through interactions with mineral surfaces, isolation from microbes, and the important role of transport in shaping soil properties and controlling moisture limitations on decomposition. As our paradigm for soil organic carbon (SOC) preservation changes, so too should our representation...
Aeolian sediments in paleowetland deposits of the Las Vegas Formation
Harland L. Goldstein, Kathleen B. Springer, Jeffrey S. Pigati, Marith C. Reheis, Gary L. Skipp
2021, Quaternary Research (104) 1-13
The Las Vegas Formation (LVF) is a well-characterized sequence of groundwater discharge (GWD) deposits exposed in and around the Las Vegas Valley in southern Nevada. Nearly monolithologic bedrock surrounds the valley, which provides an excellent opportunity to test the hypothesis that GWD deposits include an aeolian component....
Seasonal activity and diets of bats at uranium mines and adjacent areas near the Grand Canyon
Ernest W. Valdez, Mollie K Hanttula, Jo Ellen Hinck
2021, Western North American Naturalist (81) 1-18
Little information exists on the habitat use and feeding ecology of insectivorous bats in arid ecosystems, especially at and near uranium mines in northern Arizona, within the Grand Canyon watershed. In 2015–2016, we conducted mist-netting, nightly acoustic monitoring (>1 year), and diet analyses of bats,...
Stochastic inversion of gravity, magnetic, tracer, lithology, and fault data for geologically realistic structural models: Patua Geothermal Field case study
Ahinoam Pollack, Trenton T. Cladouhos, Michael W. Swyer, Drew L. Siler, Tapan Mukerji, Roland N. Horne
2021, Geothermics (95)
Financial risk due to geological uncertainty is a major barrier for geothermal development. Production from a geothermal well depends on the unknown location of subsurface geological structures, such as faults that contain hydrothermal fluids. Traditionally, geoscientists collect many different datasets, interpret the...
Hydraulic characterization of carbonate-rock and basin-fill aquifers near Long Canyon, Goshute Valley, northeastern Nevada
C. Amanda Garcia, Keith J. Halford, Philip M. Gardner, David W. Smith
2021, Scientific Investigations Report 2021-5021
Understanding groundwater flow and pumping effects near pending mining operations requires accurate subsurface hydraulic characterization. To improve conceptual models of groundwater flow and development in the complex hydrogeologic system near Long Canyon Mine, in northwestern Goshute Valley, northeastern Nevada, the U.S. Geological Survey characterized the hydraulic properties of carbonate...
Constraints on deep, CO2-rich degassing at arc volcanoes from solubility experiments on hydrous basaltic andesite of Pavlof Volcano, Alaska Peninsula, at 300 to 1200 MPa
Margaret Mangan, Thomas W. Sisson, W. Ben Hankins, Nobumichi Shimizu, Torsten W. Vennemann
2021, American Mineralogist (106) 762-773
The solubility of CO2 in hydrous basaltic andesite was examined in fO2-controlled experiments at a temperature of 1125 °C and pressures between 310–1200 MPa. Concentrations of dissolved H2O and CO2 in experimental glasses were determined by ion microprobe calibrated on a subset of run glasses analyzed by high-temperature vacuum manometry. Assuming that the...
Insights on the characteristics and sources of gas from an underground coal mine using compositional data analysis
C. Ozgen Karacan, Josep Antoni Martín-Fernández, Leslie F. Ruppert, Ricardo A. Olea
2021, International Journal of Coal Geology (241)
Coal mine gas originates from the gas emission zone (GEZ) of the mine, as well as the longwall face and pillars. Gas emissions are controlled directly at the sources using horizontal or vertical boreholes drilled from surface or from the entries in advance...
Time-domain electromagnetic soundings and passive-seismic measurements for delineation of saline groundwater in the Genesee Valley-fill aquifer system, western New York, 2016–17
John Williams, William M. Kappel, Carole D. Johnson, Eric A. White, Paul M. Heisig, John W. Lane Jr.
2021, Scientific Investigations Report 2021-5008
The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, used noninvasive surface geophysics in the investigation of the distribution of saline groundwater in the valley-fill aquifer system of the Genesee River Valley near the former Retsof salt mine in western New York. In 1994,...
Single-well production history matching and geostatistical modeling as proxy to multi-well reservoir simulation for evaluating dynamic reservoir properties of coal seams
C. Ozgen Karacan
2021, International Journal of Coal Geology (241)
Reservoir properties of coal seams such as gas and water effective permeabilities and gas content, as well as spatial distributions thereof, affect the success of gas production and CO2-enhanced gas recovery (EGR) with simultaneous CO2 sequestration. These properties change during production and injection operations due to variations in reservoir pressure, matrix shrinkage/swelling, and water saturation...
Hydrogeologic framework, geochemistry, groundwater-flow system, and aquifer hydraulic properties used in the development of a conceptual model of the Ogallala, Edwards-Trinity (High Plains), and Dockum aquifers in and near Gaines, Terry, and Yoakum Counties, Texas
Andrew P. Teeple, Patricia B. Ging, Jonathan V. Thomas, David S. Wallace, Jason D. Payne
2021, Scientific Investigations Report 2021-5009
In 2014, the U.S. Geological Survey, in cooperation with Llano Estacado Underground Water Conservation District, Sandy Land Underground Water Conservation District, and South Plains Underground Water Conservation District (hereinafter referred to collectively as the “UWCDs”), began a multiphase study in and near Gaines, Terry, and Yoakum Counties, Texas, to develop...
Three-dimensional geologic map of the Brady geothermal area, Nevada
Drew L. Siler, James E. Faulds, Nicholas H. Hinz, John H. Queen
2021, Scientific Investigations Map 3469
The three-dimensional (3D) geologic map characterizes the subsurface in the Brady geothermal area in the northern Hot Springs Mountains of northwestern Nevada. We built the 3D map by integrating the results from detailed geologic mapping, seismic-reflection, potential-field-geophysical, and lithologic well-logging investigations completed in the study area. This effort was undertaken...
3-D geologic controls of hydrothermal fluid flow at Brady geothermal field, Nevada, USA
Drew L. Siler, Jeff D. Pepin
2021, Geothermics (94)
In many hydrothermal systems, fracture permeability along faults provides pathways for groundwater to transport heat from depth. Faulting generates a range of deformation styles that cross-cut heterogeneous geology, resulting in complex patterns of permeability, porosity, and hydraulic conductivity. Vertical connectivity (a throughgoing network of permeable areas...
Implementation plan for the southern Pacific Border and Sierra-Cascade Mountains provinces
Victoria E. Langenheim, Russell W. Graymer, Robert E. Powell, Kevin M. Schmidt, Donald S. Sweetkind
2021, Open-File Report 2021-1012
IntroductionThe National Cooperative Geologic Mapping Program (NCGMP) is publishing a strategic plan titled Renewing the National Cooperative Geologic Mapping Program as the Nation’s Authoritative Source for Modern Geologic Knowledge (Brock and others, in press). The plan provides a vision, mission, and goals for the program during the years 2020–2030, which...
The formation, transport, and breakup of submerged oil-particle aggregates in Great Lakes riverine environments
John Berens, Michel C. Boufadel, Faith A. Fitzpatrick, Marcelo H. Garcia, Jacob S. Hassan, Earl Hayter, Lori Jones, Susan Mravik, David Waterman
2021, Research Brief EPA/600/S-21/061
The formation, transport, and resuspension of oil-particle aggregates (OPA) in freshwater environments are of much interest to oil spill responders and scientists, especially as transportation of light and heavy crude oils has substantially increased across river corridors and coasts in the Great Lakes Basin. The persistent sheening from accumulated OPA...
Linear deconvolution applied to ASTER imagery of terrestrial dune analog sites
Donald M. Hooper, Bernard E. Hubbard
2021, Conference Paper
Advanced Spaceborne Thermal Emission and Reflec-tion (ASTER) radiometer onboard NASA’s Terra satellite has nearly complete global coverage in the 8 – 14 µm thermal infrared (TIR) atmospheric window and is the highest resolution sensor providing TIR emissivity data at 90-m spatial resolution and five multispectral bands. ASTER imagery enables mapping...
