Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Machine learning to identify geologic factors associated with production in geothermal fields: A case-study using 3D geologic data, Brady geothermal field, Nevada
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 fluids. Transmissive fluid-flow pathways are relatively rare in the subsurface, but a
Authors
Drew L. Siler, Jeff D. Pepin, Velimir V. Vesselinov, Maruti K. Mudunuru, Bulbul Ahmmed
Relative risk of groundwater-quality degradation near California (USA) oil fields estimated from 3H, 14C, and 4He
Relative risks of groundwater-quality degradation near selected California oil fields are estimated by examining spatial and temporal patterns in chemical and isotopic data in the context of groundwater-age categories defined by tritium and carbon-14. In the Coastal basins, western San Joaquin Valley (SJV), and eastern SJV; 82, 76, and 0% of samples are premodern (pre-1953 recharge), respectively;
Authors
Peter B. McMahon, Matthew K. Landon, Tracy Davis, Michael Wright, Celia Z. Rosecrans, Robert Anders, Michael Land, Justin T. Kulongoski, Andrew Hunt
Ten years of volcanic activity at Mt Etna: High-resolution mapping and accurate quantification of the morphological changes by Pleiades and Lidar data
The topography of Mt. Etna, Italy, is subjected to continuous modifications depending on intensity and magnitude of eruptions that frequently occur at the volcano summit and flanks. In order to make high-resolution maps of morphological changes and accurately calculate the overall volume of the erupted products (e.g., lava flows, tephra fall out, scoriae cones) in ten years, we have compared the a
Authors
Marina Bisson, Claudia Spinetti, Daniele Andronico, Monica Palaseanu-Lovejoy, Maria Fabrizia Buongiorno, Oleg Alexandrov, Thomas Cecere
Comment on ‘New insights on Franciscan Complex geology, architecture, depositional age, and provenance for the western Mt. Tamalpais area, Marin County, California’ by Bero et al. (2020)
Serious errors and inconsistencies in the article undermine many of its interpretations to the point that principal conclusions are not valid. Much dependence is placed on the maximum depositional age (Dmax) of sandstone units based on zircon analysis of 10 samples, but calculation of those Dmax values is flawed, and their use confuses maximum with actual depositional ages and makes age distinctio
Authors
Russell Graymer, Trevor A. Dumitru, Robert J. McLaughlin, Carl M. Wentworth
Improving flood-frequency analysis with a 4,000-year record of flooding on the Tennessee River near Chattanooga, Tennessee
This comprehensive field study applied paleoflood hydrology methods to estimate the frequency of low-probability floods for the Tennessee River near Chattanooga, Tennessee. The study combined stratigraphic records of large, previously unrecorded floods with modern streamflow records and historical flood accounts. The overall approach was to (1) develop a flood chronology for the Tennessee River ne
Authors
Tessa M. Harden, Jim E. O'Connor, Meredith L. Carr, Mackenzie Keith
Sediment budget for watersheds of West Maui, Hawaii
Episodic runoff brings suspended sediment to West Maui’s nearshore waters, turning them from blue to brown. This pollution degrades the ecological, cultural, and recreational value of these iconic nearshore waters. We used mapping, monitoring, and modeling to identify and quantify the watershed sources for fine sediment that pollutes the nearshore each year. These results focus strategies to reduc
Authors
Jonathan D. Stock, Corina Cerovski-Darriau
Tectonostratigraphic record of late Miocene–early Pliocene transtensional faulting in the Eastern California shear zone, southwestern USA
The Eastern California shear zone (ECSZ; southwestern USA) accommodates ~20%–25% of Pacific–North America relative plate motion east of the San Andreas fault, yet little is known about its early tectonic evolution. This paper presents a detailed stratigraphic and structural analysis of the uppermost Miocene to lower Pliocene Bouse Formation in the southern Blythe Basin, lower Colorado River valley
Authors
Rebecca J. Dorsey, Brennan O'Connell, Kevin Gardner, Mindy B. Homan, Scott E. K. Bennett, Jacob Thacker, Michael H. Darin
Stochastic inversion of gravity, magnetic, tracer, lithology, and fault data for geologically realistic structural models: Patua Geothermal Field case study
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 datasets manually, and create a single model estimating faults' locations. This
Authors
Ahinoam Pollack, Trenton T. Cladouhos, Michael W. Swyer, Drew L. Siler, Tapan Mukerji, Roland N. Horne
The paleogeography of Laurentia in its early years: New constraints from the Paleoproterozoic East-Central Minnesota batholith
The ca. 1.83 Ga Trans-Hudson orogeny resulted from collision of an upper plate consisting of the Hearne, Rae, and Slave provinces with a lower plate consisting of the Superior province. While the geologic record of ca. 1.83 Ga peak metamorphism within the orogen suggests that these provinces were a single amalgamated craton from this time onward, a lack of paleomagnetic poles from the Superior pro
Authors
Nicholas L. Swanson-Hysell, Margaret Susan Avery, Yiming Zhang, Eben B. Hodgin, Robert J. Sherwood, Francisco E. Apen, Terrence J. Boerboom, C. Brenhin Keller, John M. Cottle
3-D geologic controls of hydrothermal fluid flow at Brady geothermal field, Nevada, USA
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 that allows advection of heat from
Authors
Drew L. Siler, Jeff D. Pepin
Unsaturated flow processes and the onset of seasonal deformation in slow-moving landslides
Predicting rainfall-induced landslide motion is challenging because shallow groundwater flow is extremely sensitive to the preexisting moisture content in the ground. Here, we use groundwater hydrology theory and numerical modeling combined with five years of field monitoring to illustrate how unsaturated groundwater flow processes modulate the seasonal pore water pressure rise and therefore the o
Authors
Noah J. Finnegan, Jonathan P. Perkins, Alexander Lewis Nereson, Alexander L. Handwerger
Implementation plan for the southern Pacific Border and Sierra-Cascade Mountains provinces
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 are:Vision.—Create an integrated, three
Authors
Victoria E. Langenheim, Russell W. Graymer, Robert E. Powell, Kevin M. Schmidt, Donald S. Sweetkind