Publications

Three distinct carbonate deposits have been identified on the slope and adjacent sea floor of the southwestern Florida Platform: (1) reef talus, recognized by shape and location, found on the upper slope of the Yucatan Channel and also east of the Marquesas Keys; (2) hemipelagic sediments, with complex sigmoid-oblique bed forms, filling the intervening gap between the channel and Keys...

Slumps and sediment-gravity flows have been identified in Holocene glaciomarine sediment on declivities less than 1.3 degrees on the Gulf of Alaska continental shelf. Geologic and geotechnical investigation suggest that the processes responsible for these slope failures are earthquake and storm-wave loading, coupled with cyclic degradation of the sediment-shear strength. We propose that...

A bored and encrusted late Pleistocene ooid grainstone was recovered from the seafloor at a depth of approximately 40 m on the outer continental shelf of eastern Florida. Ooid cortices are dominantly bimineralic, generally consisting of inner layers of radial magnesian calcite and outer layers of tangential aragonite. Ooid nuclei are dominantly rounded cryptocrystalline grains, although...

No abstract available.

Thirty-nine outcrop samples of mudstones, siltstones, and limestones were collected for source-rock evaluation of the sedimentary column in Vanuatu. Twenty-nine samples showing the least evidence of oxidation were selected for total organic analysis from the Miocene Matanui Group and Port Sandwich Formation in Malakula, and from the Miocene Ilava, Peteao, and Pelapa Formations in...

Slope failures and subsequent mass movements have been identified in Holocene glaciomarine sediment on declivities less than 1.3° on the Alsek prodelta, Gulf of Alaska. Isolated collapse features cover less than 10 percent of a nearshore sand deposit, in water depths less than 40 m. In contrast, sediment gravity flow deposits (disintegrative failures) cover more than 95 percent of a...

No abstract available

Deep seismic reflection and magnetic data suggest that the Gulf of Maine is underlain by four crustal blocks of differing reflection and magnetic character. Two of these blocks, the Gulf of Maine fault zone and adjacent central plutonic zone, can be correlated with Avalonian rocks in southern New England and New Brunswick. The boundary between them, the Fundy fault, projects onshore near...

87Sr/86Sr ratios determined for samples from a 350 m core of Neogene lagoonal, shallow-water limestones from Enewetak Atoll display a remarkably informative trend. Like the recently published data for Deep Sea Drilling Project (DSDP) carbonates, 87Sr/86Sr at Enewetak increases monotonically but not smoothly from the early Miocene to the Pleistocene. The data show intervals of little or...

During 1984, over 2300 km of multichannel seismic-reflection data were recorded by the U.S. Geological Survey in the western Ross Sea and Iselin Bank regions. A temporary loss and sinking of the streamer led to increasing the streamer tow depth to 20 m, which resulted in some attenuation of frequencies in the 30-50 Hz range but no significant difference in resolution of the stacked data...

Georges Bank is a shallow part of the Atlantic continental shelf southeast of New England (Emery and Uchupi, 1972, 1984). This bank, however, is merely the upper surface of several sedimentary basins overlying a block-faulted basement of igneous and metamorphic crystalline rock. Sedimentary rock forms a seaward-thickening cover that has accumulated in one main depocenter and several...

No abstract available.