Publications

Interstitial waters from Leg 22 in the Indian Ocean revealed two unique results: Site 214, on the Ninetyeast Ridge, penetrated through a 30-meter sequence of fine-grained basalt and reentered hard, silty clay containing carbonate skeletal debris. Such a basalt layer may well have been impervious and extensive enough to seal off underlying (fossil) seawater of Paleocene age. However...

Measurement of formation factor (ratio of rock resistivity to interstitial water resistivity) from sediment cores provides an indirect measurment of the tortuosity of the fluid channels in the sediments. From these measurements one can estimate the diffusion coefficient of the sediment with depth. The F (formation factor) values for Indian Ocean sediments varied from 1.6 for a clayey...

Mixed cultures of marine bacteria isolated from the sediments of Corpus Christi Harbor were examined for their ability to assimilate or precipitate radioactive zinc and cadmium from solution. Test data indicate that during summer, when bacterial activity is at a maximum, the bacteria and their metabolic byproducts play a significant role in the removal of zinc and cadmium from seawater...

To assess the area’s hydrocarbon potential, regional geologic and geophysical studies are being conducted by the U.S. Geological Survey to determine the structural framework of the United States Atlantic outer continental shelf (AOCS) north of Cape Hatteras. Preliminary interpretations of geophysical data suggest that the buried ridge under the eastern edge of the AOCS in the Baltimore...

A total of 97 new bottom gravity measurements on the continental shelf in the vicinity of Georges Bank was reduced to the simple Bouguer anomaly, using a density of 2.80 gm per cm3 for the correction. Results help substantiate the presence of mafic and felsic intrusive bodies along the northern edge of the bank. A gravity low near the center of the bank, trending northeast, corresponds...

Analyses of pore fluids from reducing environments demonstrate that reduction of SO4 is accompanied by large increases in alkalinity and strong depletion of Ca and Mg. The data are compatible with a model of replacement of Fe3+ in clay lattices by Mg from the interstitial solutions and the precipitation of pyrite. Depletions of Na in the interstitial solutions are related to Mg losses by...

Of ten Leg 13 sites studied by us, eight give definite evidence of the existence of halite-containing sediments beneath the seabed. This conclusion is based on the existence on continuous sodium and chloride enrichments in interstitial waters with depth. This is the only direct evidence of the existence of salt at these sites, for only evaporitic dolomite, gypsum, and/or anydrite were...

Regional geological and geophysical studies are being conductedby the U.S. Geological Survey to determine the structural framework of the area from Cape Hatteras to the northeastern edge of Georges Bank in order to assess the petroleum potential of the Atlantic Outer Continental Shelf. Preliminary interpretations of geophysical data and integrating gravity and magnetic data from the U.S...

Leg 10 interstitial water analyses provide new indications of the distribution of rock salt beneath the floor of the Gulf of Mexico, both confirming areas previously indicated to be underlain by salt bodies and extending evidence of salt distribution to seismically featureless areas in the Sigsbee Knolls trend and Isthmian Embayment. The criterion for presence of salt at depth is a...

The uranium concentration and isotopic composition of water and suspended sediment from the Nueces River, Nueces Bay and Corpus Christi Bay were determined by alpha-spectroscopy. The average dissolved uranium concentration and radioactivity ratio (U234/U238) of Nueces River water were determined to be 2.44 µg/1 and 1.15 respectively. Water from a tributary of the Nueces River, Cayamon...

No abstract available.