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...
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
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...
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...
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,...
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...
The role of alkali bicarbonate-sulfate brines in the genesis of carbonatite REE resources at the Bear Lodge Alkaline Complex, Wyoming
Allen K. Andersen, Danielle A. Olinger, Mitchell M. Bennett
2025, Conference Paper
Rare-earth element (REE) resources in the Bear Lodge Alkaline Complex, Wyoming, are hosted in a variably leached carbonatite dike swarm spatially related to bodies of diatreme breccia. This study examines fluid inclusions in carbonatite dikes, peripheral fluorite breccias, and smoky quartz veins to reconstruct the physiochemical conditions of REE mineralization....
Low-sulfidation epithermal deposits of the central Basin and Range Province, USA
Thomas Monecke, Lauren R. Terry, Erik Roger Tharalson, T. James Reynolds, Greg Seitter, Tadsuda Taksavasu, Eric Anderson
2025, Conference Paper
The Basin and Range Province is host to many important low-sulfidation epithermal deposits. Within this broad zone of extension, epithermal deposits are hosted by specific areas of Miocene and younger bimodal volcanism. In northern Nevada, rifting and related volcanic activity occurred in response to thermal bulging during the development of...
Improving efficiency of disease vector sampling in the field: An automatic solar-powered mosquito trapping system
Eben H. Paxton, Laura van Bergeijk
2025, Hawaii Cooperative Studies Unit Technical Report HCSU-118
Trapping mosquitoes to quantify their distribution and abundance is often a key step in monitoring dynamics of vector-borne diseases. This is the case in Hawaii, where avian malaria is devastating native forest birds that are highly susceptible to non-native diseases. However, mosquito trapping is difficult and labor intensive. A typical...
Quantitative mineral resource assessment of lithium pegmatite deposits in the Appalachian Orogen, USA
Niki E. Wintzer, Joshua Mark Rosera, Christopher S. Holm-Denoma, Dalton M. McCaffrey, Kelsey Elizabeth Crocker, Joshua Aaron Coyan, Graham W. Lederer
2025, Conference Paper
Lithium is classified as a U.S. critical mineral commodity, and its demand is projected to drastically increase through 2040, driven by electric vehicle production and energy storage applications (IEA 2021).Most global lithium production is not in the United States increasing vulnerability to a supply disruption. The U.S. Geological Survey is...
Synergy between geology and geophysics in graphite mineral resource assessment
Patricia Grace Macqueen, George N.D. Case, Paul A. Bedrosian, Jane M. Hammarstrom, Susan M. Karl, Graham W. Lederer, Elizabeth M. Bollen, John Whitmore, Dane VanDervoort, Abraham M. Emond, Logan Fusso, Philip J. Brown, Gregory J. Walsh, Keith A. Labay, Martha Stokes, Andrew Arnold Stewart
2025, Conference Paper
Graphite is designated as a critical mineral by the U.S. Government due to its essential role in modern technology and its vulnerability to supply chain disruption. To evaluate domestic graphite resources, the U.S. Geological Survey (USGS) conducted two airborne electromagnetic (AEM) surveys as part of the Earth Mapping Resources Initiative...
Mineralization processes at Escanaba Trough
Amy Gartman, Jaycee Janet Favela, Katlin Bowman Adamczyk, John Jamieson, Rob Zierenberg, Isobel Yeo
2025, Conference Paper
Escanaba Trough off northern California is the southernmost and only sediment covered segment of the Gorda Ridge. Hydrothermal mineralization was first discovered in Escanaba Trough in 1985, and subsequent investigations included the delineation of the NESCA (northern Escanaba) and SESCA (southern Escanaba) sections of Escanaba Trough, as well as drilling...
Comparing magmatism and hydrothermal alteration using magnetic modelling and stable isotopes at the Clementine porphyry copper prospect, Montana, USA
Benjamin Patrick Magnin, Julia A. McIntosh, George H. Brimhall
2025, Conference Paper, Proceedings of the 18th Biennial SGA Meeting
Recent mapping of the underexplored Clementine prospect in southwestern Montana has revealed evidence of hydrothermal alteration and mineralized breccia vein gossan interpreted to represent the upper expression of a Cretaceous, sediment-hosted copper porphyry system. The prospect is at the nexus of several Cretaceous granites, including the pre-mineralization Butte Granite and...
Complex sound scattering layer and water-column dynamics over a mesophotic coral ecosystem: Southwest Puerto Rico, U.S.A.
Olivia M. Cheriton, Curt D. Storlazzi, Clark E. Sherman, Kurt J. Rosenberger, Nikolaos V. Schizas
2025, Coral Reefs (44) 2147-2154
A nearly 5-month record of high-resolution temperature and acoustic backscatter profiles from the upper insular slope off southwest Puerto Rico reveals complex sound scattering layer (SSL) dynamics over a mesophotic coral ecosystem (MCE). The SSLs exhibited both diel and reverse diel vertical migration, thin layer (< 5 m) and multiple layer formations,...
RUSH: Rapid remote sensing Updates of land cover for Storm and Hurricane forecast models
Chak Wa Cheang, Kristin Byrd, Nicholas Enwright, Daniel D. Buscombe, Christopher R. Sherwood, Dean B. Gesch
2025, Remote Sensing (17)
Coastal vegetated ecosystems, including tidal marshes, vegetated dunes, and shrub- and forest-dominated wetlands, can mitigate hurricane impacts such as coastal flooding and erosion by increasing surface roughness and reducing wave energy. Land cover maps can be used as input to improve simulations of surface roughness in advanced hydro-morphological models. Consequently,...
GIScience in the era of Artificial Intelligence: A research agenda towards Autonomous GIS
Zhenlong Li, Huan Ning, Song Gao, Krzysztof Janowicz, Wenwen Li, Samantha Arundel, Chaowei Yang, Budhendra Bhaduri, Shaoweng Wang, A-Xing Zhu, Mark Gahegan, Shashi Shekhar, Xinyue Ye, Grant McKenzie, Guido Cervone, Michael Hodgson
2025, Annals of GIS
The advent of generative AI exemplified by large language models (LLMs) opens new ways to represent and compute geographic information and transcends the process of geographic knowledge production, driving geographic information systems (GIS) towards autonomous GIS. Leveraging LLMs as the decision core, autonomous GIS can independently generate and execute geoprocessing...
