Publications

Like hundreds of other lunar craters of probable impact origin, Copernicus contains central peaks presumed to expose rocks uplifted from beneath the crater floor. A possible analog of these peaks on Earth is the central uplift of the Sierra Madera cryptoexplosion structure, a probable impact scar (astrobleme) in stratified Permian and Cretaceous rocks of west Texas. The most conspicuous...

Directions of natural remanent magnetization are used to identify and correlate individual cooling units in the middle Tertiary ash-flow province in central and eastern Nevada and western Utah. Potassium-argon dating indicates that the minimum time between eruptions of individual but genetically related ash-flow cooling units is on the order of 0.8 m.y. As this interval is long in...

The samples and photographs returned from the Apollo 15 site show that Hadley Delta is largely underlain by breccias whose clasts are mainly fragments of coarse-grained feldspathic rocks and nonmare-type basalt. Conspicuous sets of lineaments, visible in surface and orbital photographs of Mount Hadley and Hadley Delta, may represent systematic layering or fracture sets. The mare surface...

Paleomagnetic data and potassium-argon ages indicate that the Sonoma Volcanics was erupted during the Pliocene Gilbert reversed and Gauss normal polarity epochs. The Gilbert reversed epoch is represented in the Howell Mountains east of Napa and east of St. Helena, in the mountains immediately east of the Valley of the Moon, and on the hill just north of Santa Rosa. The Gauss normal epoch...

No abstract available.

Observed gravity values, station location, terrain corrections, and Bouguer gravity data are provided in tabular form for approximately 610 gravity observations in northern Arizona. These data were used in preparation of - - Popenoe, Peter, 1968, Complete Bouguer gravity anomaly map of the area north of the Grand Canyon in Arizona: U.S. Geol. Survey open-file report.

Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided in tabular form for approximately 2460 gravity observations in south-central Arizona. "These data were used in preparation of -- Peterson, Donald L., 1968, Bouguer gravity map of parts of Maricopa, Pima, Pinal, and Yuma Counties, Arizona: U.S. Geol. Survey Geonhvs. Inv. Map GP-615.

Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided in tabular form for approximately 450 gravity observations in southwestern Utah.

Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided in tabular form for approximately 500 gravity observations in north-central Montana. These data were used in preparation of -- Peterson, Donald L. and Rambo, William L., 1967, Bouguer gravity anomaly map of the Bearpaw Mountains and vicinity, Montana: U.S. Geol. Survey open-file report.

Observed gravity values, station locations, terrain corrections and Bouguer gravity data are provided in tabular form for approximately 2,000 gravity observations in southeastern Arizona.

Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided in tabular form for approximately 840 gravity observations in the Yuma, Arizona area and for approximately 225 gravity observations in the Blythe, California area.

This collection of 37 short papers is the second published chapter of "Geological Survey Research 1972." The papers report on scientific and economic results of current work by members of the Conservation, Geologic, and Water Resources Divisions of the U.S. Geological Survey. Chapter A, to be published later in the year, will present a summary of significant results of work done ~n...