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The current expansion of resource information, particularly on "disseminated" gold, and the improved technologies now available for resource investigations should place us in an enhanced position for developing a better predictive methodology for meeting one of the important responsibilities of the U.S. Geological Survey-to examine and assess the mineral resources...

Water resources data for the 1984 water year for Missouri consist of records of stage, discharge, and water quality of lakes and reservoirs; contains records for water discharge at 112 gaging stations; stage and contents at 9 lakes and reservoirs; water quality at 71 sampling stations (including 1 lake) and...

Detailed surveys throughout San Francisco Bay over an annual cycle (1980) show that seasonal variations of phytoplankton biomass, community composition, and productivity can differ markedly among estuarine habitat types. For example, in the river-dominated northern reach (Suisun Bay) phytoplankton seasonality is characterized by a prolonged summer bloom of netplanktonic diatoms...

Effects of adherent bacteria and bacterial extracellular polymer (exopolymer) upon uptake of particle-bound Cd, Zn and Ag by the deposit-feeding clam Macoma balthica were studied in the laboratory. Amorphous iron oxyhydroxide and unaltered and alkaline-extracted sediments were used as model particulates in separate, controlled deposit-feeding experiments. In general, amounts of...

The size-dependent relationship between in vivo fluorescence (IVF) and chlorophyll a was determined for monthly phytoplankton samples from the San Francisco Bay estuary. Chlorophyll a and IVF were both measured on netplankton (>22 μm), nanoplankton (5–22 μm), and ultraplankton (<5 μm) samples that were separated with screens. IVF and chlorophyll a were linearly related for each size class,...

The interaction between ground water and surface water in wetlands is complex and depends on the hydrologic setting of the particular wetland. Hydrologic characteristics have been used in Wisconsin to classify wetlands into four categories; surface-waterdepression wetlands, surface-water-slope wetlands, ground-waterdepression wetlands, and ground-water-slope wetlands, as described by Novitzki (1978). The...

Simultaneous acquisition of surface chlorophyll-a concentrations for 39 samples from boats and Daedalus 1260 Multispectral Scanner data from a U-2 aircraft was conducted in the northern reaches of San Francisco Bay on 28 August 1980. These data were used to develop regression models for predicting surface chlorophyll-a concentrations over the...

The two estuarine systems composing San Francisco Bay have distinct zooplankton communities and seasonal population dynamics. In the South Bay, a shallow lagoon-type estuary, the copepods Acartia spp. and Oithona davisae dominate. As in estuaries along the northeast coast of the U.S., there is a seasonal succession involving the replacement...

An interagency report prepared by the U.S. Geological Survey Saudi Arabian Mission for the Ministry of Petroleum and Mineral Resources, Kingdom of Saudi Arabia. The work on which this report was based was performed in accordance with a cooperative agreement between the U.S. Geological Survey and the Ministry of Petroleum and...

Development and habitat alteration in the San Francisco Bay-Delta system have placed the remaining wetlands in jeopardy. The Bay-Delta wetlands will be mapped in a joint project of the U. S. Environmental Protection Agency (EPA) and the U. S. Fish and Wildlife Service (FWS). Maps at a 1:24,000 scale will...

No abstract available....

No abstract available...

With Smith's (1979) model of ash flow magmatism as the point of departure, quantitative regimes of crustal magmatic evolution are outlined. The average extrusive regime of ash flow magmatism operates at a rate of about 0.001 km3/yr; progressively larger episodes of increasing repose times characterize the evolution of caldera-forming eruptions....

Three samples that have a bearing on the age of horizons within the Ordovician and Silurian systems, two previously dated by the conventional K-Ar method and one by the 40Ar/39 Ar total-fusion method, have been reanalysed using the 40Ar/39Ar age-spectrum method. Conventional K-Ar and total-fusion 40Ar/39Ar ages can always be questioned because of the...

No abstract available....

Digital elevation model (DEM) data in a raster format can be used to automatically derive the drainage characteristics of an area. A procedure has been designed that is capable of operating on matrices of elevation data having no algorithmically imposed size limit, while performing within the resolution and accuracy tolerances...

The purpose of this study was to develop a methodology to be used to investigate the aquifer characteristics and water supply potential of an aquifer system. In particular, the geohydrology of northern Long Valley, New Jersey, was investigated. Geohydrologic data were collected and analyzed to characterize the site. Analysis was...

The Meshik arc is herein defined to include Eocene to earliest Miocene volcanic and hypabyssal rocks and the associated Meshik and Stepovak Formations of the central Alaska Peninsula. Igneous rocks range from basalt to dacite and yielded K-Ar ages of 48 to 22 m.y. The Meshik arc is oriented along...

A major breeding colony of northern elephant seals, Mirounga angustirostris, occurs on San Nicolas Island, California. Due to commercial hunting, elephant seals were extinct on San Nicolas Island by the end of the 19th century. Subsequent recovery of the population has been well documented (Table 1). Census data...

This volume compiles the significant findings which began to be accumulated in 1974 during offshore petroleum explorations in the Atlantic Continental Shelf. It's the first presentation of current geological data from the U.S. Atlantic Margin from the inner edge of the coastal plain to the deep sea. A seismic grid...

No abstract available....

No abstract available....

Radiolarian biostratigraphy shows that umberiferous strata overlying the Troodos ophiolite in Cyprus are Turonian in age and are thus essentially contemporaneous with similar strata that overlie the Samail ophiolite in Oman. However, this radiolarian age is markedly older than Campanian isotopic ages measured on the underlying rocks of the Troodos...

No abstract available....

No abstract available....