Publications
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Occurrence and preservation of Eocene squamariacean and coralline rhodoliths: Eau, Tonga
A widespread rhodolith facies occurs within middle Eocene limestones of Eua, Tonga (Fig. 1). These limestones, first described by Hoffmeister (1932), represent a portion of a broad, early Tertiary platform that developed in the Tonga area prior to disruption and uplift by later Tertiary plate movements (Kroenke and Tongilava 1975). Algal rhodoliths form beds several meters thick within Eocene lime
Authors
Binyamin Buchbinder, Robert B. Halley
Bottom current and sediment transport on San Pedro Shelf, California
GEOPROBE (Geological Processes Bottom Environmental) tripods were used to measure bottom currents, pressure, and light transmission and scattering and to obtain time-series photographs of the sea floor at depths of 23 m and 67 m on San Pedro shelf between 18 April and 6 June 1978. Winds were light (< 5 m/s) with a mean direction from the southwest throughout the measurement period. Hourly averaged
Authors
David E. Drake, David A. Cacchione, Herman A. Karl
Deep continental margin reflectors
In contrast to the rarity of such observations a decade ago, seismic reflecting and refracting horizons are now being observed to Moho depths under continental shelves in a number of places. These observations provide knowledge of the entire crustal thickness from the shoreline to the oceanic crust on passive margins and supplement Consortium for Continental Reflection Profiling (COCORP)-type meas
Authors
J. Ewing, J. Heirtzler, M. Purdy, Kim D. Klitgord
Ferromanganese crusts from Necker Ridge, Horizon Guyot and S.P. Lee Guyot: Geological considerations
Necker Ridge, Horizon Guyot and S.P. Lee Guyot in the Central Pacific were sampled, seismically surveyed, and photographed by bottom cameras in order to better understand the distribution, origin, and evolution of ferromanganese crusts. Necker Ridge is over 600 km long with a rugged crest, pods of sediment to 146 m thick, slopes that average 12° to 20°, and debris aprons that cover some of the low
Authors
James R. Hein, Frank T. Manheim, William C. Schwab, Alice S. Davis
New York Bight fault
High-resolution, single-channel and multichannel seismic-reflection profiles in the New York Bight provide 7 crossings of a 50-km-long fault that trends north-northeast for 30 km from its southern end, then bends northeast, and may continue northward beneath Long Island. Displacement, which is consistently down to the west, decreases upsection and suggests a growth fault. Dip of the fault is near
Authors
Deborah R. Hutchinson, John A. Grow
Block Island fault: A Paleozoic crustal boundary on the Long Island platform
A major fault cutting through most of the crust can be identified and mapped on the Long Island platform using multichannel seismic reflection profiles and magnetic data. The fault, here called the Block Island fault (BIF), strikes north-northeast, dips westward at low angle, and does not resemble the thin-skinned thrust faulting observed in the foreland of the Appalachians. The BIF is located wit
Authors
Deborah R. Hutchinson, Kim D. Klitgord, R. S. Detrick
A drowned Holocene barrier spit off Cape Ann, Massachusetts
Seismic profiles and bathymetric contours reveal a drowned barrier spit on Jeffreys Ledge off Cape Ann, Massachusetts. Seaward-dipping internal reflectors indicate that a regressive barrier formed during the early Holocene low sea-level stillstand. Preservation of the barrier spit may have been favored by its large size (as much as 20 m thick), by an ample sediment supply from unconsolidated glaci
Authors
Robert N. Oldale
Rapid postglacial shoreline changes in the western Gulf of Maine and the Paleo-Indian environment
Rapid shoreline regression and transgression along the western Gulf of Maine between 13,000 and 9000 years B.P. are inferred to have produced a nearshore marine environment low in biologic productivity. Paleo-Indians living near the coast of the Gulf were probably forced to rely on nonmarine resources landward of the late-glacial marine limit. Thus, Paleo-Indian sites of the time period in questio
Authors
Robert N. Oldale
Why deposits of longitudinal dunes are rarely recognized in the geologic record
Dunes that are morphologically of linear type, many of which are probably of longitudinal type in a morphodynamic sense, are common in modern deserts, but their deposits are rarely identified in aeolian sandstones. One reason for non-recognition of such dunes is that they can migrate laterally when they are not exactly parallel to the long-term sand-transport direction, thereby depositing cross-st
Authors
David M. Rubin, Ralph E. Hunter
Burial diagenesis: out of sight, out of mind!
No abstract available.
Authors
Peter A. Scholle, Robert B. Halley
Foraminiferal, lithic, and isotopic changes across four major unconformities at Deep Sea Drilling Project Site 548, Goban Spur
Sediment samples taken at close intervals across four major unconformities (middle Miocene/upper Miocene, lower Oligocene/upper Oligocene, lower Eocene/upper Eocene, lower Paleocene/upper Paleocene) at DSDP-IPOD Site 548, Goban Spur, reveal that coeval biostratigraphic gaps, sediment discontinuities, and seismic unconformities coincide with postulated low stands of sea level. Foraminiferal, lithic
Authors
C. Wylie Poag, Leslie A. Reynolds, James M. Mazzullo, Loyd D. Keigwin
Coupling of ocean bottom seismometers to sediment: Results of tests with the U.S. Geological Survey ocean bottom seismometer
The response of an ocean bottom seismometer (OBS) to a transient pull that excites the natural OBS-sediment coupling resonance can be modeled as a mass-spring-dashpot system in which the resonant frequency and damping are functions of instrument mass and bearing radius and of the physical properties of the sediment (primarily the shear modulus). For the very soft sediments sometimes found on the s
Authors
Anne M. Tréhu