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Publications

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Reconstructing the geomorphic evolution and sediment budget history of a dynamic barrier island: Anclote Key, Florida

Decadal to centennial variations in sediment availability are a primary driver of coastal change within barrier systems. Models help explore how barrier morphology relates to past changes in magnitude of sediment availability, but this requires insights and validation from field efforts. In this study, we investigate the progradation of Anclote Key via its morphostratigraphy, a presently dynamic b
Authors
Daniel J. Ciarletta, Jennifer L. Miselis, Julie Bernier, Arnell S. Forde, Shannon A. Mahan

Construction and modification of debris-flow alluvial fans as captured in the geomorphic and sedimentary record: Examples from the western Sangre de Cristo Mountains, south-central Colorado

Debris-flow alluvial fans are iconic features of dynamic landscapes and are hypothesized to record tectonic and climatic change. Here, we highlight their complex formation and evolution through an exemplary suite of Quaternary debris-flow alluvial fans emanating from the western range front of the Sangre de Cristo Mountains in south-central Colorado, USA. To evaluate the constructive and modifying
Authors
Sylvia Nicovich, James Schmitt, Harrison J. Gray, Ralph E. Klinger, Shannon A. Mahan

Late glacial–Younger Dryas climate in interior Alaska as inferred from the isotope values of land snail shells

The isotope values of fossil snail shells can be important archives of climate. Here, we present the first carbon (δ13C) and oxygen (δ18O) isotope values of snail shells in interior Alaska to explore changes in vegetation and humidity through the late-glacial period. Snail shell δ13C values were relatively consistent through the late glacial. However, late-glacial shell δ13C values are 2.8‰ higher
Authors
Catherine B. Nield, Yurena Yanes, Joshua D. Reuther, Daniel R. Muhs, Jeffrey S. Pigati, Joshua D. Miller, Patrick. S. Druckenmiller

Progradational-to-retrogradational styles of Palaeogene fluvial fan successions in the San Juan Basin, New Mexico

Basin-scale outcrop analyses of fluvial architecture in the Palaeogene San Juan Basin, New Mexico, document lateral and vertical trends in channel, floodplain and palaeosol characteristics. Herein, the uppermost part of the Palaeocene Nacimiento Formation and lower Eocene Cuba Mesa and Regina Members of the San Jose Formation are identified as deposits of large fluvial fans based on trends observe
Authors
Kristine L. Zellman, Piret Plink-Bjorklund, Leland Robson Spangler

Independent age estimates resolve the controversy of ancient human footprints at White Sands

Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant Ruppia cirrhosa. These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated 14C ages of terrestrial pollen collected from the sam
Authors
Jeffrey S. Pigati, Kathleen B. Springer, Jeffrey S. Honke, David Wahl, Marie Rhondelle Champagne, Susan R.H. Zimmerman, Harrison J. Gray, Vincent L. Santucci, Daniel Odess, David Bustos, Matthew R. Bennett

Geochemical evidence for evolving Proterozoic crustal thickness and orogenic styles in southwestern Laurentia

It has long been challenging for researchers to track the crustal thickness and mode(s) of crustal modification in ancient convergent margins, limiting evaluation of the tectonic styles and processes that modify continental crust during orogenesis. We present trace element igneous geochemical crustal thickness proxies that quantitatively track the crustal thickness evolution of the long-lived Prot
Authors
Ian William Hillenbrand, Karl E. Karlstrom, Michael L. Williams, Amy K. Gilmer, Wayne R. Premo, Peter B Davis

Fluorine-rich mafic lower crust in the southern Rocky Mountains: The role of pre-enrichment in generating fluorine-rich silicic magmas and porphyry Mo deposits

Fluorine-rich granites and rhyolites occur throughout the southern Rocky Mountains, but the origin of F-enrichment has remained unclear. We test if F-enrichment could be inherited from ancient mafic lower crust by: (1) measuring amphibole compositions, including F and Cl contents, of lower crustal mafic granulite xenoliths from northern Colorado to determine if they are unusually enriched in halog
Authors
Joshua Mark Rosera, Ryan Edward Frazer, Ryan D. Mills, Kristin Jacob, Sean P. Gaynor, Drew S. Coleman, G. Lang Farmer

Potential economic consequences along migratory flyways from reductions in breeding habitat of migratory waterbirds

The migration of species, often across continents, makes it difficult to quantify the cumulative effects of local- and regional-scale conservation actions. Further, variation in stakeholder interests, differing jurisdictional governance processes, priorities, and monitoring abilities across the migratory range shapes place-specific differences in management actions. These differences may lead mana
Authors
Wayne E. Thogmartin, James H. Devries, Darius J. Semmens, James E. Diffendorfer, James A. Dubovksy, Jonathan J. Derbridge, Brady J. Mattsson

Predicting burn severity for integration with post-fire debris-flow hazard assessment: A case study from the Upper Colorado River Basin, USA

Background: Burn severity significantly increases the likelihood and volume of post-wildfire debris flows. Pre-fire severity predictions can expedite mitigation efforts because precipitation contributing to these hazards often occurs shortly after wildfires, leaving little time for post-fire planning and management.Aim: The aim of this study was to predict burn severity using pre-fire conditions o
Authors
Adam Gerhard Wells, Todd Hawbaker, John Kevin Hiers, Jason W. Kean, Rachel A. Loehman, Paul F. Steblein

Guidelines for calibration of uncrewed aircraft systems imagery

Executive SummaryThis report outlines quality assurance (QA) processes, including radiometric and geometric calibration guidelines, and guidelines for data acquisition and quality control to be followed by U.S. Geological Survey (USGS) researchers for acquiring and processing uncrewed aircraft systems (UAS) data. These QA processes ensure that UAS data can be used for quantitative analysis and are
Authors
Aparajithan Sampath, Mahesh Shrestha, Michelle While, Victoria Mary Scholl

The global wildland-urban interface

The wildland–urban interface (WUI) is where buildings and wildland vegetation meet or intermingle. It is where human–environmental conflicts and risks can be concentrated, including the loss of houses and lives to wildfire, habitat loss and fragmentation and the spread of zoonotic diseases. However, a global analysis of the WUI has been lacking. Here, we present a global map of the 2020 WUI at 10 
Authors
F. Schug, Avi Bar-Massada, Amanda Renee Carlson, H. Cox, Todd Hawbaker, D. Helmers, Patrick Hostert, D. Kaim, Neda K. Kasraee, S. Martinuzzi, Miranda H. Mockrin, Kira A. Pfoch, Volker C. Radeloff

Triple oxygen isotope compositions of globally distributed soil carbonates record widespread evaporation of soil waters

The stable isotopic composition of pedogenic carbonates is central to many studies of past climate and topography, providing a basis for our understanding of Earth's terrestrial history. A core assumption of many applications of oxygen isotope values (δ18O) of pedogenic carbonate is that they reflect the δ18O value of precipitation (rain/snow). This assumption is violated if soil carbonates form i
Authors
Julia Kelson, Tyler E. Huth, Benjamin H. Passey, Naomi E. Levin, Sierra V. Petersen, Paolo Ballato, Emily J. Beverly, Daniel O. Breecker, Gregory D. Hoke, Adam M. Hudson, Ji Haoyuan, Alexis Licht, Jay Quade