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A compilation of K-Ar-ages for southern California

The purpose of this report is to make available a large body of conventional K-Ar ages for granitic, volcanic, and metamorphic rocks collected in southern California. Although one interpretive map is included, the report consists primarily of a systematic listing, without discussion or interpretation, of published and unpublished ages that may be of value in future regional and other geologic stud
Authors
Fred K. Miller, Douglas M. Morton, Janet L. Morton, David M. Miller

Digital database of microfossil localities in Alameda and Contra Costa Counties, California

The eastern San Francisco Bay region (Contra Costa and Alameda Counties, California) is a geologically complex area divided by faults into a suite of tectonic blocks. Each block contains a unique stratigraphic sequence of Tertiary sediments that in most blocks unconformably overlie Mesozoic sediments. Age and environmental interpretations based on analysis of microfossil assemblages are key factor
Authors
Kristin McDougall, Debra L. Block

U.S. Geological Survey 2013 assessment of undiscovered resources in the Bakken and Three Forks Formations of the U.S. Williston Basin Province

The Upper Devonian Three Forks and Upper Devonian to Lower Mississippian Bakken Formations comprise a major United States continuous oil resource. Current exploitation of oil is from horizontal drilling and hydraulic fracturing of the Middle Member of the Bakken and upper Three Forks, with ongoing exploration of the lower Three Forks, and the Upper, Lower, and Pronghorn Members of the Bakken Forma
Authors
Stephanie B. Gaswirth, Kristen R. Marra

Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history

This study identifies a thermal maturity anomaly within the downdip Mississippi Interior Salt Basin (MISB) of southern Mississippi, USA, through examination of bitumen reflectance data from Aptian-age strata (Sligo Formation, Pine Island Shale, James Limestone, and Rodessa Formation). U.S. Geological Survey (USGS) reconnaissance investigations conducted in 2011–2012 examined Aptian-age thermal mat
Authors
Brett J. Valentine, Paul C. Hackley, Catherine B. Enomoto, Alana M. Bove, Frank T. Dulong, Celeste D. Lohr, Krystina R. Scott

Experimental investigation of changes in methane adsorption of bitumen-free Woodford Shale with thermal maturation induced by hydrous pyrolysis

This study quantifies the effects of organic-matter (OM) thermal maturity on methane (CH4) sorption, on the basis of five samples that were artificially matured through hydrous pyrolysis achieved by heating samples of immature Woodford Shale under five different time–temperature conditions. CH4-sorption isotherms at 35 °C, 50 °C, and 65 °C, and pressures up to 14 MPa on dry, solvent-extracted samp
Authors
Haiyan Hu, Tongwei Zhang, Jaclyn D. Wiggins-Camacho, Geoffrey S. Ellis, Michael D. Lewan, Xiayong Zhang

High-resolution topography and geomorphology of select archeological sites in Glen Canyon National Recreation Area, Arizona

Along the Colorado River corridor between Glen Canyon Dam and Lees Ferry, Arizona, located some 25 km downstream from the dam, archaeological sites dating from 8,000 years before present through the modern era are located within and on top of fluvial and alluvial terraces of the prehistorically undammed river. These terraces are known to have undergone significant erosion and retreat since emplace
Authors
Brian D. Collins, Skye C. Corbett, Joel B. Sankey, Helen C. Fairley

Correlated patterns in hydrothermal plume distribution and apparent magmatic budget along 2500 km of the Southeast Indian Ridge

Multiple geological processes affect the distribution of hydrothermal venting along a mid-ocean ridge. Deciphering the role of a specific process is often frustrated by simultaneous changes in other influences. Here we take advantage of the almost constant spreading rate (65–71 mm/yr) along 2500 km of the Southeast Indian Ridge (SEIR) between 77°E and 99°E to examine the spatial density of hydroth
Authors
Edward Baker, Christophe Hémond, Anne Briais, Marcia Maia, Daniel S. Scheirer, Sharon L. Walker, Tingting Wang, Yongshun John Chen

Assessment of unconventional oil and gas resources in Northeast Mexico, 2014

Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 0.78 billion barrels of unconventional oil, 23.5 trillion cubic feet of unconventional gas, and 0.88 billion barrels of natural gas liquids in the Sabinas Basin, Burgos Basin, and Tampico-Misantla Basin provinces of northeast Mexico.
Authors
Christopher J. Schenk, Ronald R. Charpentier, Timothy R. Klett, Marilyn E. Tennyson, Stephanie B. Gaswirth, Michael E. Brownfield, Mark J. Pawlewicz, Jean Noe Weaver

Standardization of reflectance measurements in dispersed organic matter: results of an exercise to improve interlaboratory agreement

Vitrinite reflectance generally is considered the most robust thermal maturity parameter available for application to hydrocarbon exploration and petroleum system evaluation. However, until 2011 there was no standardized methodology available to provide guidelines for vitrinite reflectance measurements in shale. Efforts to correct this deficiency resulted in publication of ASTM D7708: Standard tes
Authors
Paul C. Hackley, Carla Viviane Araujo, Angeles G. Borrego, Antonis Bouzinos, Brian Cardott, Alan C. Cook, Cortland Eble, Deolinda Flores, Thomas Gentzis, Paula Alexandra Gonçalves, João Graciano Mendonça Filho, Mária Hámor-Vidó, Iwona Jelonek, Kees Kommeren, Wayne Knowles, Jolanta Kus, Maria Mastalerz, Taíssa Rêgo Menezes, Jane Newman, Mark Pawlewicz, Walter Pickel, Judith Potter, Paddy Ranasinghe, Harold Read, Julito Reyes, Genaro De La Rosa Rodriguez, Igor Viegas Alves Fernandes de Souza, Isabel Suarez-Ruiz, Ivana Sýkorová, Brett J. Valentine

Geologic framework of thermal springs, Black Canyon, Nevada and Arizona

Thermal springs in Black Canyon of the Colorado River, downstream of Hoover Dam, are important recreational, ecological, and scenic features of the Lake Mead National Recreation Area. This report presents the results from a U.S. Geological Survey study of the geologic framework of the springs. The study was conducted in cooperation with the National Park Service and funded by both the National Par
Authors
L. Sue Beard, Zachary W. Anderson, Tracey J. Felger, Gustav B. Seixas

Preliminary geologic map of Black Canyon and surrounding region, Nevada and Arizona

Thermal springs in Black Canyon of the Colorado River, downstream of Hoover Dam, are important recreational, ecological, and scenic features of the Lake Mead National Recreation Area. This report presents the results from a U.S. Geological Survey study of the geologic framework of the springs. The study was conducted in cooperation with the National Park Service and funded by both the National Par
Authors
Tracey J. Felger, L. Sue Beard, Zachary W. Anderson, Robert J. Fleck, Joseph L. Wooden, Gustav B. Seixas

Pore characteristics of Wilcox Group Coal, U.S. Gulf Coast Region: Implications for the occurrence of coalbed gas

Pore characteristics of 27 subbituminous coal samples (16 mesh splits) from the Paleocene–Eocene Wilcox Group of north Louisiana (Ouachita and Caldwell Parishes) and south Texas (Zavala County) were examined in relation to desorbed gas content. Coal gas of the Wilcox Group is primarily biogenic in origin; thermogenic gas also may be present in some areas. On an as-received basis, desorbed gas cont
Authors
Sharon M. Swanson, Maria D. Mastalerz, Mark Engle, Brett J. Valentine, Peter D. Warwick, Paul C. Hackley, Harvey E. Belkin