Publications

The Raft River valley, near the boundary of the Snake River plain with the Basin and Range province, is a north-trending late Cenozoic downwarp bounded by faults on the west, south, and east. Pleistocene alluvium and Miocene-Pliocene tuffaceous sediments, conglomerate, and felsic volcanic rocks aggregate 2 km in thickness. Large gravity, magnetic, and total field resistivity highs...

The Lisburne Group, a thick carbonate rock unit of Mississippian and Pennsylvanian age, is one of the most widespread potential reservoir rock units in northern Alaska. A comprehensive review of the Lisburne in the subsurface of the eastern Arctic Slope indicates attractive reservoir characteristics in a favorable source and migration setting where numerous trapping mechanisms appear to...

An audio-magnetotelluric (AMT) system has been developed by the U.S. Geological Survey for low-cost reconnaissance exploration of geothermal regions. This is an electromagnetic sounding technique in which the scalar or Cagniard resistivity is computed at 12 frequencies logarithmically spaced from 7.5 to 18 600 Hz. Our system uses natural source fields except at the two upper frequencies...

A method is presented for calculating the area of influence of exploratory drill holes by using the size and shape of resource targets. The solution presented is for elliptical and circular targets, but the method is applicable to any shaped target. The degree to which points have been explored depends upon their distance away from a drill hole and the possible orientations of the target...

Gravity and magnetic fields in The Geysers-Clear Lake region are interpreted in relation to the known geology and other available geophysical data. New gravity data provide additional detail with the area of geothermal steam production. Computer techniques were used for removal of the regional gravity field, anomaly enhancement, and modeling subsurface structures. The gravity field was...

Alaska, which contains about 28% of the land and continental shelf of the United States, is estimated by the U.S. Geological Survey to contain about one third of the nation's undiscovered oil and about one sixth of its undiscovered natural gas. The Survey estimates that fields discovered in Alaska through 1972 ultimately may produce about 26 billion bbl of oil and 68 Tcf of natural gas...

A tarry, benzene-soluble material is present in metal-rich veins in the Idarado mine, Ouray County, Colo., in an area not known to have petroleum resources. The material was compared chemically, spectometrically, and chromatographically with oils from four fields in the nearby Paradox basin. Each of these oil fields contains reservoir rocks equivalent to rock units known to extend...

We have made paleomagnetic measurements and investigated the magnetic mineralogy of 24 samples of basalt and diabase from Sites 319, 320, and 321 on the Nazca plate. Sample distributions, locations, and ages of overlying sediments are as follows: Site 319, Hole 319, lat 13°01.04'S, long 101°31.46'W, 2 samples, early Miocene (N8); Site 319, Hole 319A, (same coordinates and age), 12...

No abstract available.

A volcanic center covering an area of about 80 km2 near Eureka, Nev., and active in the early Oligocene, is characterized by rhyolitic, rhyodacitic. and andesitic pyroclastic rocks, lava flows, and shallow intrusive bodies. These rocks were emplaced as intertonguing and interpenetrative units during a 5-m.y. interval; most of the volcanism was in the last 3 million years of this period...

Public agencies are frequently constrained to procure goods and services in sealed tender markets. Pricing decisions of firms participating in such markets have been analyzed for both static and dynamic situations. As might be anticipated, the decision rules obtained in these analyses depend in an integral way on the firm's perception of the behavior of other market participants. It is...

Public construction and, in particular, highway construction account for a large proportion of the non-defense expenditures by the government. Con- tracts for highway construction are let almost exclusively through a sealed tender process. Competitive bidding is used to encourage price competition. There is, however, a problem in insuring that the bidder is able to deliver the product of...