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Accretionary lapilli: what’s holding them together?

Accretionary lapilli from Tagus cone, Isla Isabela, Galápagos were analyzed using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. Our main findings are (1) the lapilli formed and hardened in a few minutes while still aloft in the dispersing eruption column. (2) Palagonite rinds developed first on the basaltic glass clasts, and subsequently crystallized
Authors
Paul M. Adams, David K. Lynch, David C. Buesch

Geology and hydrocarbon potential of the Hartford-Deerfield Basin, Connecticut and Massachusetts

The Hartford-Deerfield basin, a Late Triassic to Early Jurassic rift basin located in central Connecticut and Massachusetts, is the northernmost basin of the onshore Mesozoic rift basins in the eastern United States. The presence of asphaltic petroleum in outcrops indicates that at least one active petroleum system has existed within the basin. However, to-date oil and gas wells have not been dril
Authors
James L. Coleman

Examination of the Reelfoot Rift Petroleum System, south-central United States, and the elements that remain for potential exploration and development

The Reelfoot rift is one segment of a late Proterozoic(?) to early Paleozoic intracontinental rift complex in the south-central United States. The rift complex is situated beneath Mesozoic to Cenozoic strata of the Mississippi embayment of southeastern Missouri, northeastern Arkansas, and western Tennessee and Kentucky. The rift portion of the stratigraphic section consists primarily of synrift Ca
Authors
James L. Coleman, Thomas L. Pratt

Geology and hydrocarbon potential of the Dead Sea Rift Basins of Israel and Jordan

Following its middle Miocene inception, numerous basins of varying lengths and depths developed along the Dead Sea fault zone, a large continental transform plate boundary. The modern day left-lateral fault zone has an accumulated left-lateral offset of 105 to 110 km (65 to 68 mi). The deepest basin along the fault zone, the Lake Lisan or Dead Sea basin, reaches depths of 7.5 to 8.5 km (24,500 ft
Authors
James L. Coleman, Uri S. ten Brink

Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada

Zircon geochronology is a critical tool for establishing geologic ages and time scales of processes in the Earth's crust. However, for zircons compromised by open system behavior, achieving robust dates can be difficult. Chemical abrasion (CA) is a routine step prior to thermal ionization mass spectrometry (TIMS) dating of zircon to remove radiation-damaged parts of grains that may have experience
Authors
Kathryn E. Watts, Matthew A. Coble, Jorge A. Vazquez, Christopher D. Henry, Joseph Colgan, David John

Impact of formation water geochemistry and crude oil biodegradation on microbial methanogenesis

Converting non-producible crude oil to CH4 via methanogenic crude oil biodegradation in oil reservoirs could serve as one way to increase our energy profile. Yet, field data supporting the direct relationship between methanogenesis and crude oil biodegradation are sparse. Indicators of methanogenesis, based on the formation water and gas geochemistry (e.g. alkalinity, δ13C–CO2) were compared with
Authors
Jenna L. Shelton, Jennifer C. McIntosh, Peter D. Warwick, John E. McCray

Generation and migration of Bitumen and oil from the oil shale interval of the Eocene Green River formation, Uinta Basin, Utah

The results from the recent U.S. Geological Survey assessment of in-place oil shale resources of the Eocene Green River Formation, based primarily on the Fischer assay method, are applied herein to define areas where the oil shale interval is depleted of some of its petroleum-generating potential along the deep structural trough of the basin and to make: (1) a general estimates of the amount of th
Authors
Ronald C. Johnson, Justin E. Birdwell, Tracey J. Mercier

Geology and geologic history of the Moscow-Pullman basin, Idaho and Washington, from late Grande Ronde to late Saddle Mountains time

The Moscow-Pullman basin, located on the eastern margin of the Columbia River flood basalt province, consists of a subsurface mosaic of interlayered Miocene sediments and lava flows of the Imnaha, Grande Ronde, Wanapum, and Saddle Mountains Basalts of the Columbia River Basalt Group. This sequence is ~1800 ft (550 m) thick in the east around Moscow, Idaho, and exceeds 2300 ft (700 m) in the west a
Authors
John H Bush, Dean L Garwood, Pamela Dunlap

Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada

IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional crustal structures as an aid to understanding the geologi
Authors
Kevin M. Denton, David A. Ponce

Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974

The Defense Minerals Administration (DMA), Defense Minerals Exploration Administration (DMEA), and Office of Minerals Exploration (OME) mineral exploration programs were active over the period 1950–1974. Under these programs, the Federal Government contributed financial assistance in the exploration for certain strategic and critical minerals. The information about a mining property that was colle
Authors
David G. Frank

Surface slip during large Owens Valley earthquakes

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of lateral
Authors
E.K. Haddon, C.B. Amos, O. Zielke, Angela S. Jayko, R. Burgmann