Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2494
Insights into Mountain Pass carbonatite formation from in-situ sulfur isotopes and geochemistry of sulfate and sulfide minerals Insights into Mountain Pass carbonatite formation from in-situ sulfur isotopes and geochemistry of sulfate and sulfide minerals
The Mountain Pass carbonatite stock hosts a world-class rare earth element deposit and may be classified as a carbonate-sulfate igneous rock, as it contains on average > 50 volume percent carbonate minerals and 20 to 30 volume percent sulfate minerals. The sulfates range in composition from barite to celestine and locally occur with sparse sulfide minerals. We investigate the origin of...
Authors
Erin Kay Benson, Kathryn E. Watts, Michael J. Pribil, Jay M. Thompson, Heather A. Lowers
Unprecedented burning in tropical peatlands during the 20th century compared to the previous two millennia Unprecedented burning in tropical peatlands during the 20th century compared to the previous two millennia
Tropical peatland wildfire incidence has risen in recent decades, driven by drainage for land use and intensified by severe droughts with global climate change. These disturbances have altered vegetation structure, disrupted ecosystem functioning, and increased carbon emissions, particularly in Southeast Asia. However, the long-term history and characteristics of wildfires in tropical...
Authors
Yuwan Wang, Ted R. Feldpausch, Graeme T. Swindles, Patrick Moss, Hamish A. McGowan, Thomas G. Sim, Paul J. Morris, Adam Benfield, Colin Courtney-Mustaphi, David Wahl, Encarni Montoya, Esther N. Githumbi, Euridice N. Honorio Coronado, Femke Augustijns, Gert Verstraeten, Jess O'Donnell, John Tibby, Juan C. Benavides, K. Anggi Hapsari, Karsten Schittek, Khairun Nisha Mohamed Ramdzan, Kunshan Bao, Lydia E. Cole, Lysanna Anderson, Mariusz Galka, Orijemie Emuobosa Akpo, Paul Strobel, Prabhakaran Ramya Bala, Rene Dommain, Rob Marchant, Raman Sukumar, Sakonvan Chawchai, Sarath Pullyottum Kavil, Scott Mooney, Thomas J. Kelly, Yang Gao, Apostolos Voulgarakis, Arnoud Boom, Chantelle Burton, Juan Carlos Berrio, Kelly Ribeiro, Liana O. Anderson, Mark Hardiman, Molly Spater, Susan E. Page, Angela Gallego-Sala
Stepovers and beyond: Structural control of The Geysers geothermal system and the broader Clear Lake region Stepovers and beyond: Structural control of The Geysers geothermal system and the broader Clear Lake region
Fault geometry exerts a first-order control on geothermal systems by governing stress localization, fracture development, and permeability, yet in complex fault networks or broader shear zones, the relative influence of individual geometric features is often difficult to resolve. In the northern California Coast Ranges, The Geysers geothermal field is commonly interpreted to occur within...
Authors
Benjamin L. Melosh
Miocene evolution of the Humboldt Current Miocene evolution of the Humboldt Current
Diatom records from the East Pisco Basin (EPB) of southern Peru and offshore Ocean Drilling Program (ODP) Hole 682 A reveal stepwise increases in the primary productivity of the Humboldt Current during the middle and late Miocene. Although diatoms are present back through the late middle Eocene, successively enhanced diatom production occurs during the Miocene in four steps. The first...
Authors
John A. Barron, Thomas J. DeVries, Jason J. Coenen
Is satellite-derived bathymetry vertical accuracy dependent on satellite mission and processing method? Is satellite-derived bathymetry vertical accuracy dependent on satellite mission and processing method?
This research focusses on three satellite-derived bathymetry methods and optical satellite instruments: (1) a stereo photogrammetry bathymetry module (SaTSeaD) developed for the NASA Ames stereo pipeline open-source software (version 3.6.0) using stereo WorldView data; (2) physics-based radiative transfer equations (PBSDB) using Landsat data; and (3) a modified composite band-ratio...
Authors
Monica Palaseanu-Lovejoy, Jeffrey J. Danielson, Minsu Kim, Bryan Eder, Gretchen Imahori, Curt D. Storlazzi
Advancing current understanding of Martian impact-generated hydrothermal systems through novel coupled modeling: Insights from Gale, Jezero, and other craters Advancing current understanding of Martian impact-generated hydrothermal systems through novel coupled modeling: Insights from Gale, Jezero, and other craters
Impact-generated hydrothermal systems are considered potentially habitable environments on Mars, Earth, and other planetary bodies for microbial life. However, there is an ongoing debate regarding what geological features on Mars provide definitive evidence for such systems. Although earlier studies have modeled hydrothermal processes in Martian craters, they often lacked integration...
Authors
Alexander J. Trowbridge, Simone Marchi, Joshua M. Taron, Gordon R. Osinski
The geology of Canadian potash: A critical mineral for feeding the world The geology of Canadian potash: A critical mineral for feeding the world
Potash, potassium-bearing water-soluble salt, is the primary global economic source of potassium. Potash is recognized as a critical mineral in Canada as it is the largest source of potassium used in fertilizers. It is essential for global agricultural productivity and food security. Canada is the world’s largest potash exporter with vast deposits in the widely mined Prairie Evaporite of
Authors
E.J. Matheson, Mark D. Cocker, M. E. Snyder, Craig Funk, R. Boehner, Chaowei Yang, M.P.B. Nicolas, N. W. Kruger
Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA
Exploration continues for contact-style Ni-Cu sulfide and chromitite-associated PGE mineralization in ultramafic rocks of the Stillwater Complex. At the Iron and Chrome Mountain areas, massive sulfides occur along the complex’s footwall contact and anomalous concentrations of PGE+Au are associated with the three lowermost chromitite seams. Southeast of Chrome Mountain, magmatic layering...
Authors
Allen K. Andersen, Michael Jenkins
Estimation of the accessible and useful resource base for electric-grade enhanced geothermal systems (EGS) resources of the Great Basin, USA Estimation of the accessible and useful resource base for electric-grade enhanced geothermal systems (EGS) resources of the Great Basin, USA
Scientists with the U.S. Geological Survey (USGS) recently completed a provisional assessment of the electric-grade geothermal resources associated with the low-permeability geologic formations of the Great Basin, USA, where resources are assumed to be accessible using enhanced geothermal systems (EGS) technologies (i.e., the engineering of sufficient permeability to facilitate efficient...
Authors
Erick R. Burns, Luke P. Frash, Colin F. Williams
Preventing overfitting when using tree-based methods for mapping hydrothermal favorability Preventing overfitting when using tree-based methods for mapping hydrothermal favorability
Ensemble tree-based algorithms are robust tools for estimating sparsely distributed resources with non-linear dependencies (e.g., hydrothermal systems). These algorithms naturally accommodate the threshold conditions necessary to enable and support hydrothermal systems (e.g., having sufficient heat and permeability) and are simpler than many other non-linear machine learning strategies...
Authors
Stanley Paul Mordensky, Erick R. Burns, John Lipor, Jacob DeAngelo
Structural controls on splay fault rupture dynamics during Cascadia megathrust earthquakes Structural controls on splay fault rupture dynamics during Cascadia megathrust earthquakes
Great subduction earthquakes (Mw ≥ 8.0) can generate devastating tsunamis by rapidly displacing the seafloor and overlying water column. These potentially tsunamigenic seafloor offsets result from coseismic fault slip and deformation beneath or within the accretionary wedge. The mechanics of these shallow rupture phenomena and their dependence on subduction zone properties remain...
Authors
James Burkhardt Biemiller, Alice-Agnes Gabriel, Lydia M. Staisch, Thomas Ulrich, Audrey Dunham, Erin A. Wirth, Janet Watt, Madeleine C. Lucas, Anna Ledeczi
Assessment of coastal and fluvial morphodynamic changes using Structure-for-Motion: A case study of the Sfȃntu Gheorghe Mouth (Danube Delta, Romania) Assessment of coastal and fluvial morphodynamic changes using Structure-for-Motion: A case study of the Sfȃntu Gheorghe Mouth (Danube Delta, Romania)
The ability to accurately map erosion, flooding, and habitat loss in coastal environments is crucial for formulating national strategies aimed at preventing and mitigating the impacts of natural disasters. A fundamental component of this process is the implementation of coastal morphodynamics monitoring through Structure-from-Motion (SfM) techniques, utilizing high-resolution 2D/3D data...
Authors
Andrei Gabriel Dragos, Gabriel Iordache, Florin Dutu, Monica Palaseanu-Lovejoy, Florin Pitea, Irina Stanciu, Adrian Stanica