Publications
Filter Total Items: 7238
Coastal processes and morphology of the Bering Sea coast of Alaska
No abstract available.
Authors
A. H. Sallenger, J. R. Dingler
Fresh-water cementation of a 1,000-year-old oolite
Calcite cementation of aragonite ooid sand is producing oolite on Joulters Cays, Bahamas. During the last 1,000 years, calcite cement has formed at an average rate of between 27 and 55 cm3 /m3 /yr and is derived from dissolution of ooid aragonite in fresh water. The dissolution-reprecipitation of carbonate minerals in the aquifer results in ground waters of unusually high Sr content. Sea water and
Authors
R. B. Halley, P. M. Harris
Compressional velocities from multichannel refraction arrivals on Georges Bank: northwest Atlantic Ocean
Velocities were obtained from unreversed, refracted arrivals on analog records from a 48‐channel, 3.6-km hydrophone cable (3.89 km from the airgun array to the last hydrophone array). Approximately 200 records were analyzed along 1500 km of ship track on Georges Bank, northwest Atlantic Ocean, to obtain regional sediment velocity distribution to a depth of 1.4 km below sea level. This technique pr
Authors
L. D. McGinnis, R. M. Otis
Inverse grading and hydraulic equivalence in grain-flow deposits
Inversely graded grain-flow deposits are characterized by a hydraulic equivalence that differs from that based on settling velocities or entrainment. Dispersive equivalence, derived from the dispersive pressure hypothesis on how inverse grading develops, was found to agree reasonably well with observed relationships between grain sizes and densities in grain-flow deposits. Furthermore, observed re
Authors
A. H. Sallenger
Endolith microborings and their preservation in Holocene-Pleistocene (Bahama-Florida) ooids
Holocene ooids from Joulters Ooid Shoal (Bahamas) are bored in various ways by blue-green algae that groove along the grain surface, reside just beneath the grain surface, and tunnel extensively a few tens of microns within the grain. The microborings, morphologically distinctive, are documented with scanning electron micrographs of open borings and resin casts. Gentle dissolution of ooid aragonit
Authors
Paul M. Harris, Robert B. Halley, Karen J. Lukas
Altitude-age relationships of the lunar maria
Altitudes and relative ages of mare surface units were compared to test if a systematic correlation in height of lava eruption surfaces and age might reflect a corresponding increase in depth of the magma chamber with time; in addition the altitudes were studied to shed light on the time and place of warping of mare surfaces. The laser altimeter data from the Apollo missions and relative age data
Authors
Baerbel K. Lucchitta, J. M. Boyce
Results of a reconnaissance microearthquake survey of Bucaramanga, Colombia
Six University of Wisconsin portable, continuously‐recording seismographs were operated for 3½ days in late 1976 in the Eastern Cordillera of Colombia in a 200‐km‐diameter array around Bucaramanga, where there are also three permanent stations of the Instituto Geofísico de Los Andes Colombianos. Twenty‐seven microearthquakes were recorded. Most can be well located. Only one event, located along th
Authors
W.D. Pennington, Walter D. Mooney, René van Hissenhoven, H. Meyer, J.E. Ramirez, Robert P. Meyer
Reply to discussion by Michael A. Collins, "Fresh ground water stored in aquifers under the continental shelf: implications from a deep test, Nantucket Island, Massachusetts"
We appreciate the comments made in the discussion by Michael A. Collins, regarding our paper about the anomalously low salinity of water underlying Nantucket Island. However, we feel that in his effort to justify the mathematical approach for solving salt water intrusion problems, he has overlooked several of the major points in this paper. We will try to amplify these points to
Authors
F. A. Kohout, D.F. Delaney
Collecting biologic and geologic specimens in south Florida
No abstract available.
Authors
Eugene A. Shinn
Atlas of Mars: the 1:5,000,000 map series
This atlas comprises small-scale maps and photomosaics covering the entire surface of the planet Mars. The cartographic contents are reduced-scale versions of the 1:5,000,000 topographic series of 30 quadrangles compiled by the U.S. Geological Survey in cooperation with the National Aeronautics and Space Administration (NASA).
Authors
R. M. Batson, P.M. Bridges, J.L. Inge
Preliminary summary of the U.S. Geological Survey strong-motion records from the October 15, 1979 Imperial Valley earthquake
This report summarizes the data from near-in strong-motion accelerograph stations operated by the U.S. Geological Survey in the Imperial Valley of California at the time of the October 15, 1979 Imperial Valley earthquake. The purpose of this report is to alert others as to the nature of the strong-motion data that is available from this event. In order to provide the information in a timely manner
Authors
R. L. Porcella, R.B. Matthiesen
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska: March 1979
The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.
Authors
J.B. Townshend, J.E. Papp, E.A. Sauter, S.P. Tilton