Publications
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Subducted seamounts and recent earthquakes beneath the central Cascadia forearc
Bathymetry and magnetic anomalies indicate that a seamount on the Juan de Fuca plate has been subducted beneath the central Cascadia accretionary complex and is now located ∼45 km landward of the deformation front. Passage of this seamount through the accretionary complex has resulted in a pattern of uplift followed by subsidence that has had a profound influence on slope morphology, gas hydrate s
Authors
Anne M. Tréhu, Richard J. Blakely, Mark C. Williams
The Quaternary thrust system of the northern Alaska Range
The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the northern flank of the Alaska Range, extending from Mount McKinley (Denali) eastward to the To
Authors
Sean P. Bemis, Gary A. Carver, Richard D. Koehler
Multifractal model of magnetic susceptibility distributions in some igneous rocks
Measurements of in-situ magnetic susceptibility were compiled from mainly Precambrian crystalline basement rocks beneath the Colorado Plateau and ranges in Arizona, Colorado, and New Mexico. The susceptibility meter used measures about 30 cm3 of rock and measures variations in the modal distribution of magnetic minerals that form a minor component volumetrically in these coarsely crystalline grani
Authors
Mark E. Gettings
Fluvial transport and surface enrichment of arsenic in semi-arid mining regions: examples from the Mojave Desert, California
As a result of extensive gold and silver mining in the Mojave Desert, southern California, mine wastes and tailings containing highly elevated arsenic (As) concentrations remain exposed at a number of former mining sites. Decades of weathering and erosion have contributed to the mobilization of As-enriched tailings, which now contaminate surrounding communities. Fluvial transport plays an intermit
Authors
Christopher S. Kim, David H. Slack, James J. Rytuba
Definition of Greater Gulf Basin Lower Cretaceous and Upper Cretaceous lower Cenomanian Shale Gas Assessment Unit, United States Gulf of Mexico basin onshore and state waters
An assessment unit (AU) for undiscovered continuous “shale” gas in Lower Cretaceous (Aptian and Albian) and basal Upper Cretaceous (lower Cenomanian) rocks in the USA onshore Gulf of Mexico coastal plain recently was defined by the U.S. Geological Survey (USGS). The AU is part of the Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) of the Gulf of Mexico Basin. Definition o
Authors
Kristin O. Dennen, Paul C. Hackley
Review and update of the applications of organic petrology: Part 2, geological and multidisciplinary applications
The present paper is focused on organic petrology applied to unconventional and multidisciplinary investigations and is the second part of a two part review that describes the geological applications and uses of this branch of earth sciences. Therefore, this paper reviews the use of organic petrology in investigations of: (i) ore genesis when organic matter occurs associated with mineralization; (
Authors
Isabel Suarez-Ruiz, Deolinda Flores, João Graciano Mendonça Filho, Paul C. Hackley
Extended Abstract: Geologic evaluation of regional production trends in the Upper Cretaceous Austin Chalk
The Upper Cretaceous Austin Chalk, which extends across Texas and Louisiana, is characterized by reservoirs that produce oil, gas, and in some cases, anomalously large amounts of water. Reservoirs typically have low matrix permeability and contain natural fractures. Horizontal drilling has been used to enhance and connect these fracture systems to drain the reservoir more effectively. Although the
Authors
Krystal M. Pearson
Rock fall dynamics and deposition: an integrated analysis of the 2009 Ahwiyah Point rock fall, Yosemite National Park, USA.
We analyzed a combination of airborne and terrestrial LiDAR, high-resolution photography, seismic, and acoustic data in order to gain insights into the initiation, dynamics, and talus deposition of a complex rock fall. A large (46 700 m3) rock fall originated from near Ahwiyah Point in eastern Yosemite Valley and fell a total of 730 m to the valley floor on 28 March 2009. Analyses of remote sensin
Authors
Valerie L. Zimmer, Brian D. Collins, Greg M. Stock, Nicholas Sitar
Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope
The results of short-duration formation tests in northern Alaska and Canada have further documented the energy-resource potential of gas hydrates and have justified the need for long-term gas-hydrate-production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally occurring gas hydrate to depressurization-induced or therm
Authors
Timothy S. Collett, Ray Boswell, Myung W. Lee, Brian J. Anderson, Kelly K. Rose, Kristen A. Lewis
Geology and sequence stratigraphy of undiscovered oil and gas resources in conventional and continuous petroleum systems in the Upper Cretaceous Eagle Ford Group and related strata, U.S. Gulf Coast Region
The U.S. Geological Survey (USGS) recently assessed the technically recoverable undiscovered oil and gas onshore and in State waters of the Gulf Coast region of the United States. The USGS defined three assessment units (AUs) with potential undiscovered conventional and continuous oil and gas resources in Upper Cretaceous (Cenomanian to Turonian) strata of the Eagle Ford Group and correlative rock
Authors
Russell F. Dubiel, Ofori N. Pearson, Janet K. Pitman, Krystal M. Pearson, Scott A. Kinney
Monitoring subsurface hydrologic response for precipitation-induced shallow landsliding in the San Francisco Bay area, California, USA
Intense winter storms in the San Francisco Bay area (SFBA) of California, USA often trigger shallow landslides. Some of these landslides mobilize into potentially hazardous debris flows. A growing body of research indicates that rainfall intensity-duration thresholds are insufficient for accurate prediction of landslide occurrence. In response, we have begun long-term monitoring of the hydrologic
Authors
Brian D. Collins, Jonathan D. Stock, Lisa C. Weber, K. Whitman, N. Knepprath
Bulk rock composition and geochemistry of olivine-hosted melt inclusions in the Grey Porri Tuff and selected lavas of the Monte dei Porri volcano, Salina, Aeolian Islands, southern Italy
The Aeolian Islands are an arcuate chain of submarine seamounts and volcanic islands, lying just north of Sicily in southern Italy. The second largest of the islands, Salina, exhibits a wide range of compositional variation in its erupted products, from basaltic lavas to rhyolitic pumice. The Monte dei Porri eruptions occurred between 60 ka and 30 ka, following a period of approximately 60,000 yea
Authors
Angela L. Doherty, Robert J. Bodnar, Benedetto De Vivo, Wendy A. Bohrson, Harvey E. Belkin, Antonia Messina, Robert J. Tracy