Publications

Base and precious metal ores valued in excess of $300 million have been mined from vein, pipe, and replacement deposits located on the northwest side of, and structurally related to, the middle Tertiary Silverton caldera. A belt of normal faults radial to the caldera contains veins which have been mined for as much as 15,000 feet (4,600 m) along strike and 3,700 feet (1,100 m) downdip. Structural

Fissure-filling and replacement Pb-Zn-Cu-Au-Ag ores of the Mayflower mine occur in calcareous sedimentary and intrusive wall rocks over a vertical interval of 3,000 feet. The ores are exceptional in the district for their chalcopyrite and gold content and for the unusual associated gangue minerals anhydrite, chlorite, and hematite. High oxygen fugacities are indicated for many stages of mineraliza

Suspended matter collected in the Middle Atlantic Bight (the coastal segment of the United States between Cape Cod and Cape Hatteras) in September 1969 was predominantly organic: an average of 80% combustible organic matter in surface waters and 40)% near bottom. Total suspended concentrations decreased between the inner shelf and the shelf break by an order of magnitude in both near-surface and n

Patterns of mortality and inhibition of brain and plasma ChE in birds treated with ChE inhibitors were studied in an attempt to determine the validity of using ChE activity as a monitoring and diagnostic technique. Analysis of brain ChE activity proved to be reliable for diagnosing and monitoring effects of selected ChE inhibitors in birds. Brain ChE inhibition exceeding 20% indicated exposure, an

No abstract available.

Numerous hot springs occur in a variety of geologic provinces in west-central Alaska. Granitic plutons are common to all the provinces, and the hot springs are spatially associated with the contacts of these plutons. Of 23 hot springs whose bedrock geology is known, all are within 4.8 km (3 mi) of a granitic pluton. The occurrence of hot springs, however, appears to be independent of the age, comp

More than 10 billion gallons (38 × 106 m3) of acid industrial liquid waste has been injected in about 11 years under high pressure into a saline-water-filled part of a limestone aquifer of low transmissivity between 1,400 and 1,700 feet (430 and 520 m) below land surface near Pensacola, Florida. A similar waste disposal system is planned for the same zone at a site about 8.5 miles (13.7 km) to the

In the past, humic acid has been methylated by suspending it in a solution of diazomethane in diethyl ether, and degrading the partly methylated humic acid to release those parts of the molecule that were methylated. Only small fragments of the molecule have been identified by this technique. In the procedure described here the humic acid is dissolved in 2-pyrrolidone and methylated by the additio

Detection and transmission of Infectious Hematopoietic Necrosis Virus in rainbow trout (Salmo gairdneri) was studied at a commercial trout hatchery. Transmission of virus was demonstrated via water, feed and contaminated eggs. If eggs from carrier females were incubated several weeks in virus-free water, the resulting fry did not become infected. However, if fry subsequently became infected they w

Regional development and industrialization patterns are investigated and related via regression analysis to water resource investments for the island of Puerto Rico. Although results of this study indicate such investments have little immediate or short‐term impact, significant relationships and variations in regional responses appear over longer time periods. This is shown by applying a variation

Bulgaria is in southeastern Europe between reasonably well-described areas of predominantly Alpine crustal deformation on the north and northwest (Carpathians in Romania, Hungary, and Czechoslovakia; Alps in Austria), on the east (Pontides and Taurides in Turkey), and on the west and south (Dinaric Alps in Yugoslavia; Pindos Mountains in Greece) but has not been well described in easily available

Much of the ocean floor is covered by lava of a distinctive character. The lava appears to be made up of closely packed ellipsoidal masses about the size and shape of pillows - hence the term pillow lava. Only within the last few years has the abundance of pillow lava on the ocean floor been fully recognized. Ocean-bottom photographs and dredge samples have shown that the great bulk of new ocean f