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,...
Formation of the Mount Weld rare earth deposit, Western Australia: Geochronology constraints
Philip Verplanck, Cameron Mark Mercer, Jay Michael Thompson, Martin Danišík, Ganesh Bhat, Heather A. Lowers
2025, Conference Paper
Constraining the age of protracted chemical weathering in stable cratonic areas that may form thick regoliths and the potential enrichment of various elements is challenging. Economic deposits of aluminium, iron, copper, nickel, cobalt, niobium, and rare earth elements (REEs) form in this manner. Determining the age of formation can provide...
Mine waste as a potential source of critical minerals and other commodities: Examples from the Four Corners states, USA
Jeffrey L. Mauk, Sean Patrick Gaynor, Nick Karl, Andrew Francis Smith
2025, Conference Paper
The growing demand for critical minerals and other mineral resources has raised concerns about possible supplies of these essential commodities. Mine waste is a potential source of these essential commodities. We compiled a geospatial database of publicly available data of the largest non-fuel mine waste features (>200,000 m2 in areal...
Petrogenesis and mineralization potential of the Bradley Peak komatiitic basalts, Wyoming Province
Lisa Joanne Zieman, Michael Jenkins, Michael L. Zientek, Jacob Evan Poletti, Alan D. Rooney
2025, Conference Paper
The ca. 2.72 Ga Bradley Peak greenstone terrane in the Wyoming Province contains spinifex- and cumulate-textured komatiitic volcanic rocks that may host Ni-Cu-PGE sulfide mineralization. New whole rock geochemistry classifies these rocks as Al-undepleted komatiitic basalts derived from a parental melt with ~17 wt. % MgO. Isotopic data (Sm-Nd, Re-Os)...
Mechanics and statistics of postseismic shaking
Timothy Hugh Clements, Elizabeth S. Cochran, Sarah E. Minson, Nicholas van der Elst, Clara Yoon, Annemarie S. Baltay Sundstrom, Morgan T. Page
2025, Geophysical Research Letters (52)
Analysis of two weeks of continuous post-seismic shaking after the 2019 M7.1 Ridgecrest, CA earthquake sequence using 4 nearby borehole seismometers reveals that continuous ground motions decay as Omori’s law in time and follow the Gutenberg-Richter distribution in logarithmic amplitude. The measured temporal decay in amplitudes agrees with predictions of...
Airborne radiometric data map alteration of porphyry copper systems in the Elkhorn district, MT
Eric Anderson, Kaleb Scarberry, Kyle Eastman, Jonathan Andrew Funk, Benjamin Patrick Magnin, Joseph Clevenger, John Dilles, Jarred L. Zimmerman, Snir Attia, Michael Cosca
2025, Conference Paper
The Elkhorn district in southwestern Montana is known for past production of high-grade base and precious metals from skarn and carbonate replacement deposits. The district also hosts a porphyry Cu-Mo deposit. A radiometric survey flown over the district and surrounds provides maps of surficial concentrations of potassium, thorium, and uranium....
Tracing fluid evolution during batholith and deposit formation: In-situ and bulk rock Mo isotopes from the Questa porphyry Mo deposit, New Mexico, USA
Sean Patrick Gaynor, Nicolas D. Greber, Qasid Ahmad, Pia Künzi, Ingo Horn, Stefan Weyer
2025, Conference Paper
The Oligocene Questa porphyry Mo deposit, located in New Mexico, USA, is a well-characterized system that formed over 400 kyr, punctuating the 8 Myr formation of the Questa-Latir batholith. Detailed sampling of the intrusions and minerals associated with magmatichydrothermal mineralization, as well as bookending barren intrusions, allows for examination of...
Did they feel it? Legacy maroseismic data illuminates an engimatic 20th century earthquake
Susan E. Hough, Lori Dengler, Robert McPherson, Lijam Hagos, Margaret Hellweg
2025, Earth and Space Science (12)
The challenges and the importance of preserving legacy instrumental records of earthquakes are now well-recognized (e.g., Richards & Hellweg, 2020, https://doi.org/10.1785/0220200053). Seismologists may not be aware of parallel challenges and opportunities with legacy macroseismic data for earthquakes in the United States. For much of the 20th century, macroseismic...
Shear surface undulations modulate clayey gouge strength and contribute to divergent landslide acceleration
William H. Schulz, Gonghui Wang, Yao Jiang, Brian D. Collins, Mark E. Reid, Mason Muir Einbund
2025, Engineering Geology (357)
Landslides display a spectrum of speeds for incompletely known reasons. Sliding occurs along slickensided undulatory shear surfaces within boundary shear gouge. Laboratory tests reveal that gouge shear strength generally decreases with finite cumulative displacement during relatively rapid failure and may...
A comparison of deep-sea coral and sponge species distribution models and the impact of ocean currents in the Southern California Bight
Nissa Kreidler, Andre Buchheister, David D. Huff, Jerome Fiechter, Mary Yoklavich, Mark J. Henderson
2025, Deep Sea Research Part II: Topical Studies in Oceanography (224)
Deep-sea corals and sponges (DSCS) are signature taxa of deep-water habitats, but ecological mechanisms that drive their geographic distributions can be difficult to uncover due to the challenges of surveying deep-water ecosystems and limited oceanographic data. A comparison of species distribution models was made for three DSCS...
