Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
The Earth Mapping Resources Initiative (Earth MRI): Mapping the Nation’s critical mineral resources
The Earth Mapping Resources Initiative (Earth MRI; formerly known as 3DEEP) is planned as a partnership between the U.S. Geological Survey (USGS), the Association of American State Geologists (AASG), and other Federal, State, and private-sector organizations. The goal of the effort is to improve our knowledge of the geologic framework in the United States and to identify areas that have the potent
Authors
Warren C. Day
Geophysical Characterization of the heat source in the Northwest Geysers, California
The Geysers, in northern California, is the largest energy producing geothermal field in the world. Looking to expand capacity, the operator Calpine Corporation developed an anomalously hot (~400 °C at 2.5 km depth) part of the field in the northwest Geysers, including testing of an enhanced geothermal systems (EGS). Though the area is anomalously hot, geophysical methods have failed to adequately
Authors
Jared R. Peacock, Margaret T. Mangan, Mark Walters, Craig Hartline, Jonathan M.G. Glen, Tait E. Earney, William D. Schermerhorn
Oxygen isotopic investigation of silicic magmatism in the Stillwater caldera complex, Nevada: Generation of large-volume, low-δ18O rhyolitic tuffs and assessment of their regional context in the Great Basin of the western United States
Successive caldera-forming eruptions from ca. 30 to 25 Ma generated a large nested caldera complex in western Nevada that was subsequently dissected by Basin and Range extension, providing extraordinary cross-sectional views through diverse volcanic and plutonic rocks. A high-resolution oxygen isotopic study was conducted on units that represent all major parts of the Job Canyon, Louderback Mounta
Authors
Kathryn E. Watts, David John, Joseph Colgan, Christopher D. Henry, Ilya N. Bindeman, John W. Valley
Three-dimensional geologic mapping to assess geothermal potential: Examples from Nevada and Oregon
Geologic structure plays an important role in controlling fluid flow in geothermal systems. In particular, very complex structural settings, consisting of many closely spaced and intersecting faults, host many geothermal systems. To elucidate the key geologic factors that affect fault-controlled geothermal circulation, it is critical to precisely characterize the structural and stratigraphic geome
Authors
Drew L. Siler, James E. Faulds, Nicholas H. Hinz, Gregory M. Dering, Joel H. Edwards, Brett Mayhew
Uncertainty and risk evaluation during the exploration stage of geothermal development: A review
Quantifying and representing uncertainty for geothermal systems is often ignored, in practice, during the exploration phase of a geothermal development project. We propose that this occurs potentially because the task seems so formidable. The primary goal of this paper is to initiate a dialogue within the geothermal community about: which geothermal uncertainties should receive the most attention
Authors
Jeffrey B. Witter, Whitney J. Trainor-Guitton, Drew L. Siler
Changes in the active, dead, and dormant microbial community structure across a Pleistocene permafrost chronosequence
Permafrost hosts a community of microorganisms that survive and reproduce for millennia despite extreme environmental conditions such as water stress, subzero temperatures, high salinity, and low nutrient availability. Many studies focused on permafrost microbial community composition use DNA-based methods such as metagenomic and 16S rRNA gene sequencing. However, these methods do not distinguish
Authors
Alexander Burkert, Thomas A. Douglas, Mark Waldrop, Rachel Mackelprang
Effect of permafrost thaw on plant and soil fungal community in the boreal forest: Does fungal community change mediate plant productivity response?
Permafrost thaw is leading to rapid shifts in boreal ecosystem function. Permafrost thaw affects soil carbon turnover through changes in soil hydrology, however, the biotic mechanisms regulating plant community response remain elusive. Here, we measured the response of fungal community composition and soil nutrient content in an intact permafrost plateau forest soil and an adjacent thermokarst bog
Authors
Ursel M.E Schütte, Jeremiah A. Henning, Yuzhen Ye, A. Bowling, James D. Ford, Helene Genet, Mark Waldrop, Merritt R. Turetsky, Jeffrey R. White, James D Bever
Beneath the arctic greening: Will soils lose or gain carbon or perhaps a little of both?
Ecosystem shifts related to climate change are anticipated for the next decades to centuries based on a number of conceptual and experimentally derived models of plant structure and function. Belowground, the potential responses of soil systems are less well known. We used geochemical steady state models, soil density fractionation, and soil radiocarbon data to constrain changes in soil carbon bas
Authors
Jennifer W. Harden, J.A. O’Donnell, K.A. Heckman, B.N. Sulman, C.D. Koven, C.L. Ping, G.J. Michaelson
Biological and mineralogical controls over cycling of low molecular weight organic compounds along a soil chronosequence
Low molecular weight organic compounds (LMWOC) represent a small but critical component of soil organic matter (SOM) for microbial growth and metabolism. The fate of these compounds is largely under microbial control, yet outside the cell, intrinsic soil properties can also significantly influence their turnover and retention. Using a chronosequence representing 1200 ka of pedogenic development, w
Authors
Jack McFarland, Mark P. Waldrop, Daniel Strawn, Courtney Creamer, Corey R. Lawrence, Monica Haw
The Miocene Atastra Creek sinter (Bodie Hills volcanic field, California and Nevada): 4D evolution of a geomorphically intact siliceous hot spring deposit
The Atastra Creek siliceous hot spring deposit, or sinter, occurs in the Paramount-Bald Peak alteration zone, due north of the Bodie precious metals mining district in the Miocene Bodie Hills volcanic field, California and Nevada, U.S.A. Distinctive features include its geomorphically intact geyser vent mounds, the presence of growth-fault-stepped sinter terraces that developed westward along a NN
Authors
Kathleen A. Campbell, Diego M. Guido, David John, Peter Vikre, David Rhys, Ayrton Hamilton
Crustal structure of the northern Harrat Rahat volcanic field (Saudi Arabia) from gravity and aeromagnetic data
New gravity data reveal a prominent negative anomaly along the main vent axis of the northern Harrat Rahat volcanic field in Saudi Arabia. The low continues north of the volcanic field onto exposures of Proterozoic rocks, indicating that the low is caused not only by the volcanic field (and possibly also underlying Cenozoic sediments), but also the underlying Proterozoic basement. An inversion
Authors
Victoria E. Langenheim, Brent Ritzinger, Hani M. Zahran, Adel Shareef, Maher Al-dahri
Warming effects of spring rainfall increase methane emissions from thawing permafrost
Methane emissions regulate the near‐term global warming potential of permafrost thaw, particularly where loss of ice‐rich permafrost converts forest and tundra into wetlands. Northern latitudes are expected to get warmer and wetter, and while there is consensus that warming will increase thaw and methane emissions, effects of increased precipitation are uncertain. At a thawing wetland complex in I
Authors
Rebecca B. Neumann, C.J. Moorberg, J.D. Lundquist, J.C. Turner, Mark P. Waldrop, Jack W. McFarland, E.S. Euskirchen, C.W. Edgar, M. R. Turetsky