Paleoproterozoic vein graphite mineralization caused by decarbonation in the Ruby Range, Montana, USA
George N.D. Case, Jay Michael Thompson, Sean P. Regan
2025, Conference Paper
Hydrothermal graphite veins are a possible source for modern battery materials and require better understanding of their carbon source(s) and absolute timing to develop mapable criteria for exploration models. We present new observations of graphite vein and alteration paragenesis and U-Pb LA-ICP-MS titanite age data from the Ruby prospect, Montana,...
Re-Os geochronology of molybdenite by LA-ICP-MS/MS
Amanda Souders, Jay Michael Thompson
2025, Conference Paper
Re-Os geochronology is a powerful tool to directly date sulphide mineralisation using phases such as molybdenite, pyrite and chalcopyrite. We present a snapshot of a method in development utilizing laser ablation inductively coupled-plasma ‘triple quad’ mass spectrometry (LA-ICP-MS/MS) for Re-Os geochronology of molybdenite. While traditional LA-(MC)-ICP-MS measurements are limited by...
Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad
Garth E. Graham, Erik Roger Tharalson
2025, Conference Paper
Basin-hosted Zn-Pb deposits, including MVT and clastic-dominated (CD or “Sedex”) Zn-Pb deposits are major sources of Zn and Pb, as well as other critical elements. We examined available whole rock and sphalerite chemistry data to understand the apparent variation of Ga and Ge among major current and historical districts of...
40Ar/39Ar geochronology supporting mineral resources research at USGS Denver
Leah E. Morgan, Cameron Mark Mercer
2025, Conference Paper
The 40Ar/39Ar geochronology method is used to date potassium-bearing rocks and minerals, based on the decay of 40K to 40Ar, which provides important temporal constraints for geological events. The USGS Denver Argon Geochronology Laboratory dates samples from a variety of projects, mainly in the USGS Mineral Resource Program and the...
Seamless Geologic Map Database for the Intermountain West, United States: A foundational dataset for mineral systems analysis
Amy K. Gilmer, Kenzie J. Turner, Jeremiah B. Workman, Ren A. Thompson, Theresa Maude Schwartz, Chester A. Ruleman
2025, Conference Paper
The Intermountain West has a complex geologic history, resulting in the formation of a diverse array of mineral deposits. Effective mineral exploration requires understanding the spatial and temporal relationships among geologic processes and events, a key focus of the mineral systems approach to exploration. This paper presents the Intermountain West...
Ages and trace element fertility of porphyry-related mineralization in the Philipsburg polymetallic district, Montana, with a comparison to Butte
Celine M.E. Beaucamp, Christopher H. Gammons, Jay Michael Thompson, Holly J. Stein
2025, Conference Paper
The Philipsburg mining district is a Mo-Cu porphyry system with associated Cordilleran polymetallic veins. Geochronology was employed to date the porphyry (~66 Ma, U/Pb in zircon) and molybdenite mineralization from the veins (~76 Ma, Re-Os). Age results suggest that the two-mineralization events model proposed by Lund et al. (2018) for the...
Pre- and post-eruptive geochemical and isotopic fingerprints of rhyolites parental to volcano-sedimentary lithium brine and clay resources in the western USA & central Andes
Celestine N. Mercer, Regina Marie Khoury, Julie Roberge, Madison Myers
2025, Conference Paper
Lithium is a high-demand, critical element used not only in lightweight rechargeable lithium-ion batteries, but also in nuclear applications and industries producing ceramics, aluminum, and medical products. It is extracted primarily from pegmatites and volcano-sedimentary brines and clays in arid, closed lacustrine or caldera basins. Lithium brines of the central...
Water temperature regimes and thermal drivers in semi-natural and flow-regulated rivers of the northern Great Plains
Patrick Braaten, T. David Ritter, Tyler M. Haddix, David B. Fuller, John R. Hunziker, John G. Hargrave
2025, River Research and Applications (41) 2073-2091
Rivers of the northern Great Plains have lacked long-term, continuous water temperature assessments, and there is limited information on thermal regimes of these systems and factors driving water temperature. We collected and assembled 2001–2022 water temperature data from 18 sites on four reaches of three rivers that differ in anthropogenic...
Stable isotope composition and geochemistry of calcite and dolomite in the Mountain Pass carbonatite: A lens into petrogenesis
Erin Kay Benson, Kathryn E. Watts, Jay Michael Thompson, Heather A. Lowers
2025, Conference Paper
Carbonatites host most of the global rare earth element (REE) deposits. The petrogenesis of these rocks, including magmatic and post-magmatic processes, are poorly understood but critical in forming and upgrading these deposits. The Mountain Pass carbonatite, which hosts the only active REE mine in North America, is lithologically variable but...
Hyperspectral imaging of river bathymetry using an ensemble of regression trees
Carl J. Legleiter, Paul J. Kinzel, Brandon Overstreet, Lee R. Harrison
2025, Earth Surface Processes and Landforms (50)
Remote sensing has emerged as an effective tool for characterizing river systems, and machine learning (ML) techniques could make this approach even more powerful. To explore this possibility, we developed an ML-based workflow for hyperspectral imaging of river bathymetry using an ensemble of regression trees (HIRBERT). This approach involves using...
Scientific opportunities in the National Landscape Conservation System
Sarah K. Carter, Sarah E. Whipple, Samuel E. Jordan, Nicole M. Herman-Mercer, Robin C. Lewis, Karen L. Prentice, Zachary H. Bowen, Frederick L. Klasner
2025, Parks Stewardship Forum (41) 388-401
The National Landscape Conservation System consists of unique and beautiful places across America’s landscapes where identified resources and values are protected and science is highlighted. The mission of the National Landscape Conservation System (NLCS), which is managed by the Bureau of Land Management and is often referred to as the...
Evaluation of the acute toxicity of the piscicide TFM to Burbot
Nicholas Schloesser, James A. Luoma, Courtney Kirkeeng, Samantha L. Wolfe, Justin Schueller, Hannah Mann Thompson
2025, Journal of Wildlife Management (89)
Non-target animal sensitivity remains a concern when treating Laurentian Great Lakes streams with 4-nitro-3-(trifluoromethyl)phenol (TFM), the main pesticide used to control Sea Lamprey Petromyzon marinus as part of the bi-national Great Lakes Fishery Commission's Sea Lamprey Control Program. Populations of Burbot Lota lota, a historically and culturally important fish, inhabit some of the...
A soil velocity model for improved ground motion simulations in the U. S. Pacific Northwest
Alex R. Grant, Erin A. Wirth, Ian P. Stone
2025, Seismica (4)
Near-surface seismic velocity structure may significantly impact the intensity, duration, and frequency content of ground shaking during an earthquake. In this study, we compile 649 shear wave velocity (Vs) profiles throughout the U.S. Pacific Northwest and southern British Columbia (PNW) and use these measured profiles to develop a representative soil...
Decision support tools for brown pelican management in the northern Gulf of America (Gulf of Mexico)
James P. Cronin, Blair E. Tirpak, Leah L. Dale, Virginia L. Robenski, John M. Tirpak, Barry C. Wilson, William G. Vermillion, Donald R. Schoolmaster Jr.
2025, Journal of Wildlife Management (89)
Management plans with clear priorities can help to achieve brown pelican Pelecanus occidentalis conservation objectives in the northern Gulf of America (Gulf of Mexico). Efforts to establish clear priorities can be hindered by information gaps, especially those related to the uncertainty associated with changing conditions that influence brown pelican populations. We addressed...
Population structure and movement dynamics of Redband Trout in the Kootenai River basin
Courtnie L. Ghere, Malte Willmes, Ryan S. Hardy, Tyler J. Ross, James Dunnigan, Sean Wilson, Scott Carleton, Michael C. Quist
2025, River Research and Applications (41) 2218-2233
Redband Trout Oncorhynchus mykiss gairdneri is a species of high conservation concern in the Kootenai River basin, United States and Canada. However, identifying the specific mechanisms influencing Redband Trout is difficult as its life history structure is largely unknown. Using otolith microchemistry analysis, we found that 18.5% (n = 66) of...
Breeder turnover, harvest, and food affect recruitment of young nonbreeders in groups of gray wolves
David Edward Ausband
2025, Animal Conservation
Groups of cooperative breeders typically have social hierarchies, with breeders at the top guiding group decisions and influencing the behavior of subordinates in the group. Because of breeders' strong influence on group dynamics and behaviors, breeder turnover can affect the survival of remaining group members. We lack...
Uppermost Oligocene and Miocene diatom biostratigraphy of Ocean Drilling Program Sites 682 and 688 from the Peru Margin
Jason Coenen, John A. Barron, Thomas J. DeVries
2025, Stratigraphy (22) 155-180
The diatom biochronology of ODP (Ocean Drilling Program) Holes 682A and 688E provides a detailed framework for refiningMiocene diatom zonation in the East Pisco Basin of southern Peru, establishing both a nearly complete offshore reference section and a correlation tool for the fragmentary onshore vertebrate-bearing deposits. This new biostratigraphic record...
Calcareous nannofossil biostratigraphy and floral response to environmental changes recorded in the Pliocene Yorktown Formation, southeastern Virginia, USA
Masayuki Utsunomiya, Harry J. Dowsett
2025, Stratigraphy (22) 181-193
The Pliocene Yorktown Formation, deposited on the U.S. Mid-Atlantic Coastal Plain, has played an important role in advancing our knowledge of Pliocene paleoclimate. To refine the age and paleoenvironment of the Yorktown Formation, we analyzed the calcareous nannofossil assemblage and compared it with variations in lithology and calculated sea surface...
Reframing fish passage prioritization for human nutrition outcomes
Nicolette Duncan, Ana Horta, John Conallin, Tim Marsden, Abigail J. Lynch, Ivor Stuart
2025, Environmental Management (75) 3401-3417
Water control infrastructure forms barriers that fragment river habitats, reducing aquatic biodiversity and the ecosystem services it provides. Irrigation infrastructure, for example, although implemented to support food production, highlights problematic trade-offs against wild food systems like inland fisheries which are a critical food resource for tens of millions of people,...
Alteration mapping in granitic gneiss using handheld geophysical and geochemical instruments: Implications for iron oxide-apatite and rare earth elements exploration
Kaitlyn A. Suarez, Michael L. Williams, Gregory J. Walsh, Daniel E. Harlov, Michael J. Jercinovic, Daniel J. Tjapkes, Ian William Hillenbrand
2025, Ore and Energy Resource Geology (19)
The Adirondack Mountains of New York, U.S.A. contain iron oxide-apatite (IOA) mineral deposits with variable concentrations of rare earth elements (REE). The IOA mineral deposits are typically hosted in the Lyon Mountain Granite Gneiss and are spatially correlated with extensive Na metasomatism (albitization) of the surrounding country rocks,...
Toward a new framework to evaluate process-based model configurations and quantify data worth prior to calibration
Mark Shannon Pleasants, Michael N. Fienen, Hedeff I. Essaid, Joel D. Blomquist, Jing Yang, Ming Ye
2025, Water Resources Research (61)
Model criticism, discrimination, and selection methods often rely on calibrated model outputs. Because calibration can be computationally expensive, model criticism can first be undertaken by assessing model outputs obtained from limited prior parameter ensembles. However, such prior-based methods are often heuristic and do not formalize the notion of balancing model...
Summary of selenium in the lower Gunnison River Basin, Colorado—Information and data gaps
Rachel G. Gidley, Kenneth J. Leib, Cory A. Williams
2025, Circular 1559
The Cretaceous Mancos Shale is a geologic source of selenium in the lower Gunnison River Basin. Natural weathering processes and human activity mobilize selenium from the Mancos Shale and derived materials, and surface water, groundwater, and sediment all affect the transport of selenium from source areas to receiving streams and...
Enhancing mineral systems exploration through geochronology, thermochronology, and isotope analysis: USGS Geochron and USGS Isotope databases
Kelly David Thomson, Ian William Hillenbrand, Amy K. Gilmer, Leah E. Morgan, Zachary T. Engle, Anna T. Miller
2025, Conference Paper
A mineral systems approach to mineral exploration provides a comprehensive framework for understanding ore deposit formation by examining the geodynamic, magmatic, hydrothermal, and sedimentary processes responsible for mineralization, alteration, and remobilization of economic mineral deposits. Temporal and thermal constraints on ore genesis are crucial for refining mineral system models and...
Origin of the high Pd/Pt ratio of the J-M Reef, Stillwater Complex Montana USA
Michael Jenkins, William D. Smith
2025, Conference Paper
The J-M Reef of the Stillwater Complex exhibits a high and consistent Pd/Pt ratio (~3.8). This ratio results from the equilibration of an immiscible sulfide liquid with a relatively high Pd/Pt silicate melt rather than an unusually Pd- and Pt-enriched parental melt. Numerical modeling suggests that the original silicate melt...
Evidence for offset of Cretaceous plutons by the Tintina fault in eastern Alaska: Implications for regional metallogeny
Douglas C. Kreiner, Erin Todd, James V. Jones III, Christopher S. Holm-Denoma, Laura Pianowski, Paul O’Sullivan
2025, Conference Paper
Cretaceous magmatism in eastern interior Alaska is voluminous, but temporally and spatially diverse – suggestive of varying sources and drivers. More than 150 new U-Pb zircon and more than 500 geochemical analyses of Cretaceous plutonic units allow for the grouping of distinct plutonic suites. Magmatism was continuous from 120-66 Ma...
