Publications
Filter Total Items: 2672
Reconnaissance landslide map of the Healdsburg 15-minute Quadrangle, Sonoma County, California
No abstract available.
Authors
Carl M. Wentworth
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
In situ stress, natural fracture distribution, and borehole elongation in the Auburn Geothermal Well, Auburn, New York
Hydraulic fracturing stress measurements and a borehole televiewer survey were conducted in a 1.6‐km‐deep well at Auburn, New York. This well, which was drilled at the outer margin of the Appalachian Fold and Thrust Belt in the Appalachian Plateau, penetrates approximately 1540 m of lower Paleozoic sedimentary rocks and terminates 60 m into the Precambrian marble basement. Analysis of the hydrauli
Authors
Stephen H. Hickman, John H. Healy, Mark D. Zoback
Well bore breakouts and in situ stress
The detailed cross-sectional shape of stress induced well bore breakouts has been studied using specially processed ultrasonic borehole televiewer data. Breakout shapes are shown for a variety of rock types and introduce a simple elastic failure model which explains many features of the observations. Both the observations and calculations indicate that the breakouts define relatively broad and fla
Authors
Mark D. Zoback, Daniel Moos, Larry Mastin, Roger N. Anderson
Book review: Methods of rock magnetism and palaeomagnetism
Book information: Methods of rock magnetism and palaeomagnetism — Techniques and instrumentation: D.W. Collinson. Chapman and Hall, London, 1983, xiv + 503 pp.
Authors
Ray E. Wells
Paleomagnetism and geology of Eocene volcanic rocks of southwest Washington, implications for mechanisms of tectonic rotation
Paleomagnetic and geologic investigations in Eocene volcanic rocks of the southwest Washington Coast Range demonstrate a close relationship between tectonic rotations and the local structural geology. The allochthonous middle Eocene submarine basalt basement of the Crescent Formation consists of several fault‐bounded structural domains up to 30 km across that are characterized by different amounts
Authors
Ray E. Wells, Robert S. Coe
The Steens Mountain (Oregon) geomagnetic polarity transition: 1. Directional history, duration of episodes, and rock magnetism
The thick sequence of Miocene lava flows exposed on Steens Mountain in southeastern Oregon is well known for containing a detailed record of a reversed‐to‐normal geomagnetic polarity transition. Paleomagnetic samples were obtained from the sequence for a combined study of the directional and intensity variations recorded; the paleointensity study is reported in a companion paper. This effort has r
Authors
Edward A. Mankinen, M. Prevot, C. Sherman Grommé, Robert S. Coe
The Steens Mountain (Oregon) geomagnetic polarity transition, 2. Field intensity variations and discussion of reversal models
We carried out an extensive paleointensity study of the 15.5±0.3 m.y. Miocene reversed‐to‐normal polarity transition recorded in lava flows from Steens Mountain (south central Oregon). One hundred eighty‐five samples from the collection whose paleodirectional study is reported by Mankinen et al. (this issue) were chosen for paleointensity investigations because of their low viscosity index, high C
Authors
M. Prevot, Edward A. Mankinen, Robert S. Coe, C. Sherman Grommé
Bibliography of United States landslide maps and reports
No abstract available.
Authors
C.S. Alger, E. E. Brabb
Correlation of metamorphosed Paleozoic strata of the southeastern Mojave Desert region, California and Arizona: Discussion and reply
No abstract available.
Authors
H.J. Brown, Paul Stone, Keith A. Howard, Warren Hamilton
Geology of the Ruby Mountains-East Humboldt Range, Nevada: A Cordilleran metamorphic core complex
No abstract available.
Authors
A.W. Snoke, Keith A. Howard
Canyon-filling lavas and lava dams on the Boise River, Idaho, and their significance for evaluating downcutting during the last 2 million years
Basalts that periodically dammed the Boise River and its South Fork over the last 2 million years reveal the canyon history and illustrate how lava interacted with impounded river water. Intracanyon basalt flows record a granite canyon successively filled by lava and then recut at least five times in the last 2 million years. The most voluminous flow, Steamboat Rock Basalt, reached 60 kilometers d
Authors
Keith A. Howard, John W. Shervais, E. H. McKee