Publications
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The non-transferability of a Cretaceous coal model in the San Juan Basin of New Mexico and Colorado
The San Juan Basin of northwest New Mexico and southwest Colorado contains several Upper Cretaceous coal-bearing formations. The coals in these formations were deposited in environments associated with repeated transgressions and regressions of the Western Interior seaway in Late Cretaceous time. A detailed subsurface and surface study of the coal beds in one of these units, the Fruitland Formatio
Authors
James E. Fassett
Volcanic rocks as sources of uranium: Current perspective and future directions
No abstract available.
Authors
Robert A. Zielinski
Fluorine in Colorado oil shale
Oil shale from the lower part of the Eocene Green River Formation in the Piceance Creek Basin, Colorado, averages 0.13 weight percent fluorine, which is about twice that found in common shales, but is the same as the average amount found in some oil shales from other parts of the world. Some fluorine may reside in fluorapatite; however, limited data suggest that cryolite may be quantitatively more
Authors
John R. Dyni
Recognition of interstitial anhydrite dissolution: A cause of secondary porosity, San Andres limestone, New Mexico, and Upper Minnelusa Formation, Wyoming
Rectangular and stair-step pore reentrants in carbonate mudstones have been recognized previously as indirect evidence for anhydrite dissolution. In this study, direct evidence for subsurface dissolution of interstitial anhydrite in both dolomite grainstones and quartz sandstones includes: (1) cleavage-related dissolution fringe on anhydrite crystal surfaces, and (2) isolated remnants of optically
Authors
Christopher J. Schenk, Randall W. Richardson
Brief comparison of some technological and environmental aspects of large-scale surface and underground mining of oil shale, Piceance Creek Basin, Colorado
Comparison of several aspects of surface and underground methods of mining for large-scale oil shale extraction in the Piceance Creek Basin suggests that surface mining techniques may have several advantages over underground methods. For a production level of one million barrels of shale oil per day, potential advantages include those related to economics, environmental effects, and the overall na
Authors
G.A. Miller, John R. Dyni, D.R. Dietz
Distribution and origin of sulfur in Colorado oil shale
The sulfur content of 1,225 samples of Green River oil shale from two core holes in the Piceance Creek Basin, Colorado, ranges from nearly 0 to 4.9 weight percent. In one core hole, the average sulfur content of a sequence of oil shale 555 m thick, which represents nearly the maximum thickness of oil shale in the basin, is 0.76 weight percent. The vertical distribution of sulfur through the oil sh
Authors
John R. Dyni
The Frontier Formation and mid- Cretaceous orogeny in the foreland of southwestern Wyoming
Tectonism in SW Wyoming and adjoining areas, and fluctuations of sea level in the central USA during the mid-Cretaceous are represented by the regional stratigraphy of the Frontier Formation. The Frontier consists mainly of clastic rocks that were deposited in marine and nonmarine environments during latest Albian, Cenomanian, Turonian, and Coniacian time. -from Author
Authors
E. Allen Merewether
Iridium abundance measurements across the Cretaceous/Tertiary boundary in the San Juan and Raton Basins of northern New Mexico
During the past year we have been measuring trace element abundances and searching for anomalously high iridium (Ir) concentrations in continental sedimentary rocks that span the Cretaceous-Tertiary boundary in the Raton and San Juan Basins of northern New Mexico and southern Colorado. Using neutron activation and radiochemical separations, we have identified anomalous concentrations of Ir in samp
Authors
C. J. Orth, J. S. Gilmore, J.D. Knight, R.H. Tschudy, C. L. Pillmore, James E. Fassett
Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska
U-Th-Pb analyses of zircons from an ortho-augen gneiss body in the Yukon-Tanana Upland of east-central Alaska yield strong evidence for the presence of early Proterozoic material in this area. U-Pb data define a chord that intersects concordia at about 2,300 and 345 m.y. We consider two interpretations: (1) the protolith was intruded during the Proterozoic and was subsequently metamorphosed in the
Authors
John N. Aleinikoff, Cynthia Dusel-Bacon, Helen L. Foster, Kiyoto Futa
Processed and interpreted U.S. Geological Survey seismic reflection profile and vertical seismic profiles, Niobrara County, Wyoming
No abstract available.
Authors
Myung W. Lee, J. J. Miller, R. T. Ryder, A. H. Balch
Processed and interpreted U.S. Geological Survey seismic reflection profile and vertical seismic profile, Powder River and Carter Counties, Montana
No abstract available.
Authors
John J. Miller, R. T. Ryder, A. H. Balch, M. W. Lee
Uranium contents of glassy and devitrified andesites and dacites, Mount Mazama, Oregon
By direct comparison of devitrified and granophyrically crystallized specimens with nonhydrated glassy materials from the same units, Rosholt and coworkers (Rosholt and Noble, 1969; Rosholt et al., 1971) showed that specimens of primarily crystallized but otherwise unaltered peralkaline and subalkaline rhyolite from the western United States had lost from 30 to 80 percent of the uranium that they
Authors
D. C. Noble, W.I. Rose, Robert A. Zielinski