Publications
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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
Geologic estimates and future costs of strip mining coal
Geologic coal-resource appraisals, which typically describe the location and general characteristics of coalbeds, do not generally provide enough information to estimate the cost of developing the resource or to predict the escalation of costs expected to result from physical depletion. This paper considers the nature of data and methods of appraisal required to provide this cost information to po
Authors
E. D. Attanasi, E.K. Green
Paleomagnetic study of some Cretaceous and Tertiary sedimentary rocks of the Klamath Mountains province, California
Paleomagnetic investigation of Cretaceous outliers and Tertiary sedimentary strata of the Klamath Mountains province, and of onlapping Cretaceous strata, has shown the rocks to be largely remagnetized. Samples studied are from the Upper Jurassic to Upper Cretaceous Great Valley sequence, Upper Cretaceous Hornbrook Formation, Eocene Montgomery Creek Formation, and Oligocene(?) Weaverville Formation
Authors
Edward A. Mankinen, William P. Irwin
Paleomagnetic data from the Coso Range, California and current status of the Cobb Mountain normal geomagnetic polarity event
Two basalt flows which erupted about 1.08 m.y. ago in the Coso Range, California, have normal magnetic polarity and thus provide additional evidence for the Cobb Mountain normal polarity event. A review of available data confirms that this event was of geomagnetic origin. A mean age of 1.10 ± 0.02 m.y. B.P. for the Cobb Mountain normal polarity event was found to best fit all available radiometric
Authors
Edward A. Mankinen, C. Sherman Grommé
Post 12 m.y. rotation of southwest Washington
Paleomagnetic field directions from the basalt of Pack Sack Lookout are compared to those from the Pomona Member of the Saddle Mountains Basalt of the Columbia River Basalt Group. The Pomona crops out over a wide region on the Columbia Plateau east of the Cascade Range, and the basalt of Pack Sack Lookout crops out well to the west of the Cascades about 30 to 60 km east of the Washington coast. Ou
Authors
James R. Magill, Ray E. Wells, Robert W. Simpson, Allan Cox
Preliminary geology of the Bristol Lake region, Mojave Desert, California
No abstract available.
Authors
D. M. Miller, Keith A. Howard, B.E. John
Depositional setting and diagenetic evolution of some Tertiary unconventional reservoir rocks, Uinta Basin, Utah
The Douglas Creek Member of the Tertiary Green River Formation underlies much of the Uinta basin, Utah, and contains large volumes of oil and gas trapped in a complex of fractured low-permeability sandstone reservoirs. In the southeastern part of the basin at Pariette Bench, the Eocene Douglas Creek Member is a thick sequence of fine-grained alluvial sandstone complexly intercalated with lacustrin
Authors
Janet K. Pitman, T. D. Fouch, M. B. Goldhaber
Preliminary tectonostratigraphic terrane map of California
No abstract available.
Authors
M.C. Blake, D. G. Howell, David Lawrence Jones
Evaluation of potential surface faulting and other tectonic deformation
No abstract available.
Authors
M. G. Bonilla
Water-soluble material on aerosols collected within volcanic eruption clouds
In February and March of 1978, filter samplers mounted on an aircraft were used to collect the aerosol fraction of the eruption clouds from three active Guatemalan volcanoes (Fuego, Pacaya, and Santiaguito). The samples were collected on Teflon (Fluoropore) filters with a nominal pore diameter of 0.5μm. The mass of air sampled by the filters ranged from 0.15 to 6.6 kg. The particulate material col
Authors
D. B. Smith, R. A. Zielinski, W.I. Rose, B.J. Huebert
Mid-Cretaceous radiolarians in Perapedhi Formation
No abstract available.
Authors
W. P. Irwin, B. L. Murchey, D. L. Jones, S.A. Kling
In the southwest: Tectonic evolution reviewed
No abstract available.
Authors
D. M. Miller, Keith A. Howard, M. D. Carr