Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 1331

Holocene paleohydrology from alpine lake sediment, Emerald Lake, Wasatch Plateau of central Utah, USA

Holocene sediments at Emerald Lake in central Utah (3090 m asl) document the paleohydroclimatic history of the western Upper Colorado River headwater region. Multi-proxy analyses of sediment composition, mineralogy, and stable isotopes of carbonate (δ18O and δ13C) show changes in effective moisture for the past ca. 10,000 years at millennial to decadal timescales. Emerald Lake originated as a shal
Authors
Lesleigh Anderson, Gary L. Skipp, Laura E. Strickland, Jeffrey S. Honke, Jeremy C Havens, D. Paco Van Sistine

Seasonality of precipitation in the southwestern United States during the late Pleistocene inferred from stable isotopes in herbivore tooth enamel

The late Pleistocene was a climatically dynamic period, with abrupt shifts between cool-wet and warm-dry conditions. Increased effective precipitation supported large pluvial lakes and long-lived spring ecosystems in valleys and basins throughout the western and southwestern U.S., but the source and seasonality of the increased precipitation are debated. Increases in the proportions of C4/(C4+ C3)
Authors
Matthew J. Kohn, Kathleen B. Springer, Jeffrey S. Pigati, Linda Reynard, Amanda E. Drewicz, Justin Crevier, Eric Scott

Last Glacial Maximum and early deglaciation in the Stura Valley, southwestern European Alps

We combined data from geomorphologic surveys, glacial modelling, and 10Be exposure ages of boulders on moraines, to investigate the Last Glacial Maximum (LGM) and the early retreat glacial phases in the Stura Valley of the Maritime Alps. We used the exposure ages to reconstruct the timing of standstills or readvances which interrupted the post-LGM withdrawal, initiated ∼24 ka. We mapped and dated
Authors
Adriano Ribolini, Matteo Spagnolo, Andrew J. Cyr, Paolo Roberto Federici

Guide for interpreting and reporting luminescence dating results

The development and application of luminescence dating and dosimetry techniques have grown exponentially in the last several decades. Luminescence methods provide age control for a broad range of geological and archaeological contexts and can characterize mineral and glass properties linked to geologic origin, Earth-surface processes, and past exposure to light, heat, and ionizing radiation. The a
Authors
Shannon A. Mahan, Tammy M. Rittenour, Michelle S. Nelson, Nina Ataee, Nathan D. Brown, Regina DeWitt, Julie Durcan, Mary Evans, James K. Feathers, Marine Frouin, Guillaume Guérin, Maryam Heydari, Sebastien Huot, Mayank Jain, Amanda Keen-Zebert, Bo Li, Gloria I. López, Christina Neudorf, Naomi Porat, Kathleen Rodrigues, Andre O. Sawakuchi, Joel Q. G Spencer, Kristina Thomsen

The influence of soil development on the depth distribution and structure of soil microbial communities.

Although it has been shown that the interaction of climate and time shape the dynamics of soil organic matter (SOM) storage and preservation in soil, the role of soil microbial communities in this dynamic remains unclear. Microbial communities are present throughout soil profiles and likely play critical roles in SOM and nutrient cycling, however the influence of other factors such as soil develop
Authors
Mary-Catherine Leewis, Corey Lawrence, Marjorie S. Schulz, Malak M. Tfaily, Christian Orlando Ayala-Ortiz, Gilberto E. Flores, Rachel Mackelprang, Jack McFarland

Wind turbine wakes can impact down-wind vegetation greenness

Global wind energy has expanded 5-fold since 2010 and is predicted to expand another 8–10-fold over the next 30 years. Wakes generated by wind turbines can alter downwind microclimates and potentially downwind vegetation. However, the design of past studies has made it difficult to isolate the impact of wake effects on vegetation from land cover change. We used hourly wind data to model wake and n
Authors
James E. Diffendorfer, Melanie K. Vanderhoof, Zachary H. Ancona

Astrochronology of the Paleocene-Eocene Thermal Maximum on the Atlantic Coastal Plain

The chronology of the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma) remains disputed, hampering complete understanding of the possible trigger mechanisms of this event. Here we present an astrochronology for the PETM carbon isotope excursion from Howards Tract, Maryland a paleoshelf environment, on the mid-Atlantic Coastal Plain. Statistical evaluation of variations in calcium content and magnet
Authors
Mingsong Li, Timothy J. Bralower, Lee R. Kump, Jean Self-Trail, James C. Zachos, William D. Rush, Marci M. Robinson

Mountain rivers reveal the earthquake hazard of geologic faults in Silicon Valley

The 1989, Mw = 6.9 Loma Prieta earthquake resulted in tens of lives lost and cost California almost 3% of its gross domestic product. Despite widespread damage, the earthquake did not clearly rupture the surface, challenging the identification and characterization of these hidden hazards. Here, we show that they can be illuminated by inverting fluvial topography for slip-and moment accrual-rates—f
Authors
Felipe Aron, Samuel Johnstone, Andreas Mavrommatis, Robert M. Sare, Frantz Maerten, Jack Loveless, Curtis W Baden, George E. Hilley

Using ecosystem services to identify inequitable outcomes in migratory species conservation

Biodiversity conservation efforts have been criticized for generating inequitable socio-economic outcomes. These equity challenges are largely analyzed as place-based problems affecting local communities directly impacted by conservation programs. The conservation of migratory species extends this problem geographically since people in one place may benefit while those in another bear the costs of
Authors
Charles C. Chester, Aaron M. Lien, Juanita Sundberg, James E. Diffendorfer, Columba Gonzales, Brady J. Mattsson, Rodrigo Medellin, Darius J. Semmens, Wayne E. Thogmartin, Jonathan J. Derbridge, Laura López-Hoffman

Democratizing macroecology: Integrating unoccupied aerial systems with the National Ecological Observatory Network

Macroecology research seeks to understand ecological phenomena with causes and consequences that accumulate, interact, and emerge across scales spanning several orders of magnitude. Broad-extent, fine-grain information (i.e., high spatial resolution data over large areas) is needed to adequately capture these cross-scale phenomena, but these data have historically been costly to acquire and proces
Authors
Michael J. Koontz, Victoria Mary Scholl, Anna I Spiers, Megan E Cattau, John Adler, Joseph McGlinchy, Tristan Goulden, Brett A Melbourne, Jennifer K. Balch

Field-trip guide to continental arc to rift volcanism of the southern Rocky Mountains—Southern Rocky Mountain, Taos Plateau, and Jemez Mountains volcanic fields of southern Colorado and northern New Mexico

The southern Rocky Mountains of northern New Mexico and southern Colorado preserve the Oligocene to Pleistocene record of North American continental arc to rift volcanism. The 35–23 million year old (Ma) southern Rocky Mountain volcanic field (SRMVF), spectacularly preserved in the San Juan Mountains of southern Colorado, records the evolution of large andesitic stratovolcanoes to complex caldera
Authors
Ren A. Thompson, Kenzie J. Turner, Peter W. Lipman, John A. Wolff, Michael A. Dungan

Depositional controls on detrital zircon provenance: An example from upper Cretaceous strata, southern Patagonia

Understanding how depositional environments within a sedimentary system redistribute and sequester sediment is critical for interpreting basin-scale provenance trends. However, sedimentary source-to-sink models commonly examine temporal changes and do not consider how variation in sedimentation processes across a dispersal pathway may result in contrasting provenance signatures. In this paper, we
Authors
Stephen C. Dobbs, Matthew A. Malkowski, Theresa Maude Schwartz, Zachary T. Sickmann, Stephan A. Graham