Publications
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Assessment of undiscovered conventional oil resources of the East Gobi, Nyalga, Tamtsag-Hailar, Erlian, and Yingen basins of Mongolia and China, 2018
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 187 million barrels of oil and 85 billion cubic feet of gas in the East Gobi, Nyalga, Tamtsag-Hailar, Erlian, and Yingen basins of Mongolia and China.
Authors
Christopher J. Schenk, Tracey J. Mercier, Janet K. Pitman, Thomas M. Finn, Cheryl A. Woodall, Kristen R. Marra, Phuong A. Le, Heidi M. Leathers-Miller
Geology and geologic history: Overview of the geology of the San Francisco Bay region
The geology of San Francisco and the surrounding northern and central California area has played a pivotal role in the development of our understanding of Earth processes, especially the process of tectonic accretion at a continental margin and the development of transform plate margins. The Franciscan Complex, which underlies most (or perhaps all) of the City and County of San Francisco, is wide
Authors
Russell Graymer
Flushing of the deep Pacific Ocean and the deglacial rise of atmospheric CO2 concentrations
During the last deglaciation (19,000–9,000 years ago), atmospheric CO2increased by about 80 ppm. Understanding the mechanisms responsible for this change is a central theme of palaeoclimatology, relevant for predicting future CO2 transfers in a warming world. Deglacial CO2 rise hypothetically tapped an accumulated deep Pacific carbon reservoir, but the processes remain elusive as they are undercon
Authors
Jianghui Du, Brian Haley, Alan Mix, Maureen Walczak, Summer K. Praetorius
Global and Arctic climate sensitivity enhanced by changes in North Pacific heat flux
Arctic amplification is a consequence of surface albedo, cloud, and temperature feedbacks, as well as poleward oceanic and atmospheric heat transport. However, the relative impact of changes in sea surface temperature (SST) patterns and ocean heat flux sourced from different regions on Arctic temperatures are not well constrained. We modify ocean-to-atmosphere heat fluxes in the North Pacific and
Authors
Summer K. Praetorius, Maria A. Rugenstein, Geeta Persad, Ken Caldeira
Millennial soil retention of terrestrial organic matter deposited in the Bengal Fan
The abundance of organic carbon (OC) in vegetation and soils (~2,600 PgC) compared to carbon in the atmosphere (~830 PgC) highlights the importance of terrestrial OC in global carbon budgets. The residence time of OC in continental reservoirs, which sets the rates of carbon exchange between land and atmosphere, represents a key uncertainty in global carbon cycle dynamics. Retention of terrestrial
Authors
Katherine L. French, Christopher Hein, Negar Haghipour, Lukas Wacker, Hermann Kudrass, Timothy Eglinton, Valier Galy
Assessment of undiscovered continuous oil and gas resources in the Upper Cretaceous Tuscaloosa marine shale of the U.S. Gulf Coast, 2018
Using a geology-based assessment methodology, the U.S. Geological Survey assessed mean undiscovered, technically recoverable continuousresources of 1.5 billion barrels of oil and 4.6 trillion cubic feet of gas in the Upper Cretaceous Tuscaloosa marine shale in onshore and State waters ofLouisiana, Mississippi, Alabama, and Florida in the U.S. Gulf Coast region.
Authors
Paul C. Hackley, Catherine B. Enomoto, Brett J. Valentine, William A. Rouse, Celeste D. Lohr, Frank T. Dulong, Javin J. Hatcherian, Sean T. Brennan, William H. Craddock, Thomas M. Finn, Stephanie B. Gaswirth, Phuong A. Le, Heidi M. Leathers-Miller, Kristen R. Marra, Tracey J. Mercier, Stanley T. Paxton, Katherine J. Whidden, Cheryl A. Woodall, Christopher J. Schenk
Gas emissions, tars, and secondary minerals at the Ruth Mullins and Tiptop coal mine fires
Both the Tiptop and Ruth Mullins coal fires, Kentucky, were reinvestigated in 2009 and 2010. The Tiptop fire was not as active in 2009 and may have been on the path to burning out at the time of the 2009 visit. The Ruth Mullins coal mine fire, Perry County, Kentucky, has been the subject of several field investigations, including November 2009–February 2010 investigations in which we measured gas
Authors
Jennifer M. K. O'Keefe, Erika R. Neace, Maxwell L. Hammond, James C. Hower, Mark A. Engle, Joseph A. East, Nicholas J. Geboy, Ricardo A. Olea, Kevin R. Henke, Gregory C. Copley, Edward W. Lemley, Rachel S. Hatch Nally, Antonia E. Hansen, Allison R. Richardson, Anne B. Satterwhite, Glenn B. Stracher, Larry F. Radke, Charles Smeltzer, Christopher Romanek, Donald R. Blake, Paul A. Schroeder, Stephen D. Emsbo-Mattingly, Scott A. Stout
Carving Grand Canyon’s inner gorge: A test of steady incision versus rapid knickzone migration
A recent study posits that much of the 240-m-deep inner gorge of Grand Canyon was carved between 500 and 400 ka via passage of a migrating knickzone with incision rates of ~1600 m/Ma during that time period; this was based on dating of a ca. 500 ka travertine deposit perched on the rim of the inner gorge, near Hermit Rapid, and a ca. 400 ka travertine drape that extends to within 60 m of river lev
Authors
Ryan S. Crow, Karl E. Karlstrom, Laura J. Crossey, Victor Polyak, Yemane Asmerom, William C. McIntosh
Subseasonal variations in marine reservoir age from pre-bomb Donax obesulus and Protothaca asperrima shell carbonate
Two Donax obesulus and two Protothaca asperrima shells collected prior to the nuclear testing of the 1950's were micromilled at sub-seasonal resolution to yield new reservoir effect (ΔR) estimates for the coast of Peru. Shells from northern (4°40′S to 8°14′S) and central (13°52′S) Peru produced ΔR values of 123 ± 50 and 110 ± 49 years respectively. We found such values statistically indistinguisha
Authors
Miguel F. Etayo-Cadavid, C. Fred T. Andrus, Kevin B. Jones, Gregory W. L. Hodgins
Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with historical 1‐min (2‐min Nyquist) geomagnetic variation time
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
Cadmium isotope fractionation during coal combustion: Insights from two U.S. coal-fired power plants
Coal combustion, one of the principal energy sources of electricity in the United States, produces over 100 million tons of coal combustion products (CCPs) per year in the U.S. The reuse and disposal of CCPs has the potential to release toxic trace elements, including cadmium (Cd), into the environment. In this study, we investigated CCPs, including bottom ash (BA), economizer fly ash (EFA), and f
Authors
Fotio Fouskas, Ma Lin, Mark A. Engle, Leslie F. Ruppert, Nicholas J. Geboy, Matthew A. Costa
Outburst floods provide erodability estimates consistent with long-term landscape evolution
Most current models for the landscape evolution over geological timescales are based on semi-empirical laws that consider riverbed incision proportional to rock erodability (dependent on lithology) and to the work performed by water flow (stream power). However, the erodability values obtained from these models are entangled with poorly known conditions of past climate and streamflow. Here we use
Authors
Daniel Garcia-Castellanos, Jim E. O'Connor