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Determining quantity and quality of retained oil in mature marly chalk and marlstone of the Cretaceous Niobrara Formation by low-temperature hydrous pyrolysis

Low-temperature hydrous pyrolysis (LTHP) at 300°C (572°F) for 24 h released retained oils from 12- to 20-meshsize samples of mature Niobrara marly chalk and marlstone cores. The released oil accumulated on the water surface of the reactor, and is compositionally similar to oil produced from the same well. The quantities of oil released from the marly chalk and marlstone by LTHP are respectively 3.
Authors
Michael Lewan, Mark D. Sonnenfeld

Geochemical variations during development of the 5.46 Ma Broadwell Mesa basaltic volcanic field, California

The 5.46±0.04 Ma Broadwell Mesa basalt and associated basaltic volcanic field in the western Bristol Mountains, California, formed a ~6 km2 volcanic flow field with architecture including numerous lava flows, a ~1.1 km2 lava lake, and a ~0.17 km2 cinder cone. The local number of lava flows varies from one along the margins of the field to as many as 18 that are stacked vertically, onlapped by you
Authors
David C. Buesch

Connecting the Soda–Avawatz and Bristol–Granite Mountains faults with gravity andaeromagnetic data, Mojave Desert, California

The Soda–Avawatz and Bristol–Granite Mountains faults are considered by some to form the northeastern margin of the eastern California shear zone yet their connectivity and extents are obscured by surficial deposits and the estimates of total right-lateral offset from geologic data range from 0 to as much as 24 km. We use gravity and recently released detailed aeromagnetic data to map strands of t
Authors
Victoria E. Langenheim, David M. Miller

Impact-related microspherules in Late Pleistocene Alaskan and Yukon “muck” deposits signify recurrent episodes of catastrophic emplacement

Large quantities of impact-related microspherules have been found in fine-grained sediments retained within seven out of nine, radiocarbon-dated, Late Pleistocene mammoth (Mammuthus primigenius) and bison (Bison priscus) skull fragments. The well-preserved fossils were recovered from frozen “muck” deposits (organic-rich silt) exposed within the Fairbanks and Klondike mining districts of Alaska, US
Authors
Jonathan T. Hagstrum, Richard B. Firestone, Allen West, James C. Weaver, Ted E. Bunch

The hyper-enrichment of V and Zn in black shales of the Late Devonian-Early Mississippian Bakken Formation (USA)

Black shales of the Late Devonian to Early Mississippian Bakken Formation are characterized by high concentrations of organic carbon and the hyper-enrichment (> 500 to 1000s of mg/kg) of V and Zn. Deposition of black shales resulted from shallow seafloor depths that promoted rapid development of euxinic conditions. Vanadium hyper-enrichments, which are unknown in modern environments, are likely th
Authors
Clint Scott, John F. Slack, Karen Duttweiler Kelley

Bacterial sulfur disproportionation constrains timing of neoproterozoic oxygenation

Various geochemical records suggest that atmospheric O2 increased in the Ediacaran (635–541 Ma), broadly coincident with the emergence and diversification of large animals and increasing marine ecosystem complexity. Furthermore, geochemical proxies indicate that seawater sulfate levels rose at this time too, which has been hypothesized to reflect increased sulfide oxidation in marine sediments cau
Authors
Marcus Kunzmann, Thi Hao Bui, Peter W. Crockford, Galen P. Halverson, Clint Scott, Timothy W. Lyons, Boswell A. Wing

Procedure for calculating estimated ultimate recoveries of wells in the Mississippian Barnett Shale, Bend Arch–Fort Worth Basin Province of north-central Texas

In 2015, the U.S. Geological Survey published an assessment of technically recoverable continuous oil and gas resources of the Mississippian Barnett Shale in the Bend Arch–Fort Worth Basin Province of north-central Texas. Of the two assessment units involved in the overall assessment, one included a roughly equal number of oil wells and gas wells as classified by the U.S. Geological Survey’s stand
Authors
Heidi M. Leathers-Miller

Geologic characterization of the hydrocarbon resource potential of the Upper Cretaceous Tuscaloosa marine shale in Mississippi and Louisiana, U.S.A.

Recent oil production from the Upper Cretaceous Tuscaloosa marine shale (TMS) has elevated the formation, previously assessed by the USGS in 2011 as part of the Eagle Ford Group, to its own distinct assessment unit for an upcoming assessment. Geologic characterization in preparation for the 2017 assessment has included the analysis of rock samples and produced oils, and the interpretation of well
Authors
Catherine B. Enomoto, Paul C. Hackley, Brett J. Valentine, William A. Rouse, Frank T. Dulong, Celeste D. Lohr, Javin J. Hatcherian

Geology and assessment of undiscovered oil and gas resources of the Zyryanka Basin Province, 2008

The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the Zyryanka Basin Province as part of the 2008 USGS Circum-Arctic Resource Appraisal program. The province is in the Russian Federation and is situated on the Omolon superterrane of the Kolyma block. The one assessment unit (AU) that was defined for this study, called the Zyryanka Basin AU,
Authors
Timothy R. Klett, Janet K. Pitman

Geology and assessment of undiscovered oil and gas resources of the Lena-Vilyui Basin Province, 2008

The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the Lena-Vilyui Basin Province, north of the Arctic Circle, as part of the Circum-Arctic Resource Appraisal program. The province is in the Russian Federation and is situated between the Verkhoyansk fold-and-thrust belt and the Siberian craton. The one assessment unit (AU) defined for this s
Authors
Timothy R. Klett, Janet K. Pitman