Comparison of geoelectrical/tectonic models for suture zones in the western U.S.A. and eastern Europe: are black shales a possible source of high conductivities?
W. D. Stanley
1989, Physics of the Earth and Planetary Interiors (53) 228-238
Large-scale geoelectrical anomalies have been mapped with geomagnetic depth sounding (GDS) and magnetotelluric (MT) surveys in the Carpathian Mountains region. These anomalies are associated with the zone of closure between stable Europe and a complex of microplates in front of the converging African plate. The zone of closure, or suture...
Thermodynamics of magnesian calcite solid-solutions at 25°C and 1 atm total pressure
Eurybiades Busenberg, Niel Plummer
1989, Geochimica et Cosmochimica Acta (53) 1189-1208
The stability of magnesian calcites was reexamined, and new results are presented for 28 natural inorganic, 12 biogenic, and 32 synthetic magnesian calcites. The magnesian calcite solid-solutions were separated into two groups on the basis of differences in stoichiometric solubility and other physical and chemical properties. Group I consists...
Origin of Sr, Nd and Pb isotopic systematics in high-Sr basalts from central Arizona
J.H. Wittke, D. Smith, J. L. Wooden
1989, Contributions to Mineralogy and Petrology (101) 57-68
Alkalic and tholeiitic basalts were erupted in the central Arizona Transition Zone during Miocene-Pliocene time before and after regional faulting. The alkalic lava types differ from the subalkaline lavas in Sr, Nd and Pb isotopic ratios and trace element ratios and, despite close temporal and spatial relationships, the two types...
Seismic reflection images of the crust of the northern part of the Chugach terrane, Alaska: Results of a survey for the Trans-Alaska Crustal Transect (TACT)
M. A. Fisher, T.M. Brocher, W. J. Nokleberg, George Plafker, G.L. Smith
1989, Journal of Geophysical Research Solid Earth (94) 4424-4440
Deep crustal seismic reflection data show strong reflections from the middle and lower crust of the convergent continental margin near the eastern end of the Aleutian trench. These data were collected across the Border Ranges fault system, a major suture zone that separates the Peninsular and Chugach tectonostratigraphic terranes. The...
Geologic review. Better regulation through interagency cooperation
John E. Johnston, James D. Rives, David M. Soileau
1989, Conference Paper, Coastal Zone: Proceedings of the Symposium on Coastal and Ocean Management
The Geologic Review procedure was developed by the Louisiana Geological Survey (LGS) in 1982 for the Louisiana Coastal Management Division. It consists of a thorough review of oil and gas well applications involving impact to environmentally sensitive areas such as wetlands. The applicant attends a meeting with a geologist and...
The Alabama, U.S.A., seismic event and strata collapse of May 7, 1986
L.T. Long, C.W. Copeland
1989, Pure and Applied Geophysics PAGEOPH (129) 415-421
On May 7, 1986, the residents of Tuscaloosa, Alabama, felt a seismic event of local magnitude 3.6 that occurred at the same time as a rock burst and roof collapse in an active longwall coal mine. Visual inspection of the seismograms reveals a deficiency in energy at frequencies above 20...
Extraction of terrain features from digital elevation models
Curtis V. Price, David M. Wolock, Mark A. Ayers
1989, Conference Paper
Digital elevation models (DEMs) are being used to determine variable inputs for hydrologic models in the Delaware River basin. Recently developed software for analysis of DEMs has been applied to watershed and streamline delineation. The results compare favorably with similar delineations taken from topographic maps. Additionally, output from this software...
Volume predictability of historical eruptions at Kilauea and Mauna Loa volcanoes
C.-Y. King
1989, Journal of Volcanology and Geothermal Research (38) 281-285
Cumulative volumes of eruptions at the Kilauea and Mauna Loa volcanoes in Hawaii appear to fit a volume-predictable model (i.e., the volume of an eruption episode is approximately proportional to the time since the previous episode) for many larger episodes during long periods of time (decades). This observation suggests that...
West Virginia Geological Survey's role in siting fluidized bed combustion facilities
C.J. Smith, Hobart M. King, K. C. Ashton, D.S. Kirstein, G.H. McColloch
1989, Conference Paper
A project is presented which demonstrates the role of geology in planning and siting a fluidized bed combustion facility. Whenever a project includes natural resource utilization, cooperation between geologists and design engineers will provide an input that could and should save costs, similar to the one stated in our initial...
A terracing operator for physical property mapping with potential field data
L. Cordell, A. E. McCafferty
1989, Geophysics (54) 621-634
The terracing operator works iteratively on gravity or magnetic data, using the sense of the measured field's local curvature, to produce a field comprised of uniform domains separated by abrupt domain boundaries. The result is crudely proportional to a physical-property function defined in one (profile case) or two (map case)...
Dune migration in a steep, coarse-bedded stream
Randy L. Dinehart
1989, Water Resources Research (25) 911-923
During 1986 and 1987, migrating bed forms composed of coarse sand and fine gravel (d50=1.8 to 9.1 mm) were documented in the North Fork Toutle River at Kid Valley, Washington, at flow velocities ranging from 1.6 to 3.4 m s−1 and depths of 0.8 to 2.2 m. The bed forms (predominantly...
Radiometric calibration of Landsat Thematic Mapper multispectral images
P.S. Chavez Jr.
1989, Photogrammetric Engineering and Remote Sensing (55) 1285-1294
A main problem encountered in radiometric calibration of satellite image data is correcting for atmospheric effects. Without this correction, an image digital number (DN) cannot be converted to a surface reflectance value. In this paper the accuracy of a calibration procedure, which includes a correction for atmospheric scattering, is tested....
Use of the variable gain settings on SPOT
P.S. Chavez Jr.
1989, Photogrammetric Engineering and Remote Sensing (55) 195-201
Often the brightness or digital number (DN) range of satellite image data is less than optimal and uses only a portion of the available values (0 to 255) because the range of reflectance values is small. Most imaging systems have been designed with only two gain settings, normal and high....
Significance of new potassium-argon ages from the Goldens Ranch and Moroni Formations, Sanpete-Sevier Valley area, central Utah
I. J. Witkind, R. F. Marvin
1989, Geological Society of America Bulletin (101) 534-548
Exposures of volcanic-sedimentary strata are widely distributed within central Utah. We believe that these volcanic and stratified sedimentary rocks, known by different formational names in different parts of this region, are, in fact, segments of one and the same suite of rocks that formed during the early and middle Tertiary.The...
New evidence for polyphase metamorphism of glaucophane schist and eclogite exotic blocks in the Franciscan Complex, California and Oregon
Diane E. Moore, M.C. Blake Jr.
1989, Journal of Metamorphic Geology (7) 211-228
The early metamorphic history of high-grade exotic blocks in the Franciscan Complex may be more complicated than previously supposed. The different assemblages of high-grade glaucophane schists, eclogite, amphibolite and hornblende schist are commonly considered to have formed at the same time from essentially unmetamorphosed oceanic crust. However, new textural and...
Spectral analysis and filtering techniques in digital spatial data processing
Jeng-Jong Pan
1989, Photogrammetric Engineering and Remote Sensing (55) 1203-1207
A filter toolbox has been developed at the EROS Data Center, US Geological Survey, for retrieving or removing specified frequency information from two-dimensional digital spatial data. This filter toolbox provides capabilities to compute the power spectrum of a given data and to design various filters in the frequency domain. Three...
Estimating urban flood-frequency characteristics
M.E. Jennings, J.B. Atkins, E. J. Inman
1989, Conference Paper
Methods in use by the U.S. Geological Survey to estimate flood-frequency characteristics for urban watersheds are compared with estimates based on the Soil Conservation Service TR-55 model. Data from four small urban watersheds in Georgia are used in the flood-peak and hydrograph comparisons....
A hybrid fast Hankel transform algorithm for electromagnetic modeling
W.L. Anderson
1989, Geophysics (54) 263-266
A hybrid fast Hankel transform algorithm has been developed that uses several complementary features of two existing algorithms: Anderson's digital filtering or fast Hankel transform (FHT) algorithm and Chave's quadrature and continued fraction algorithm. A hybrid FHT subprogram (called HYBFHT) written in standard Fortran-77 provides a simple user interface to...
Nitrogen dynamics in the tidal freshwater Potomac River, Maryland and Virginia, water years 1979-81
David J. Shultz
1989, Water Supply Paper 2234-J
On an annual basis, river-supplied nitrate is the predominant form of nitrogen supplied to the tidal Potomac River from external sources. Much of the nitrate is associated with high flows that have rapid transit times through the tidal river. The Blue Plains Sewage-Treatment Plant (STP) at Washington, D.C., is the...
Depositional history of the Lagniappe Delta, northern Gulf of Mexico
J. L. Kindinger
1989, Geo-Marine Letters (9) 59-66
The northern Gulf of Mexico continental shelf is characterized by superimposing deltas. One such delta, informally named Lagniappe, extends east of the Mississippi Delta from mid-shelf to the continental slope. This late Wisconsinan delta is adjacent to, but not associated with the Mississippi Delta complex: the fluvial source was probably...
Regionalization of flood characteristics
W.O. Thomas Jr., M. N. Landers
1989, Conference Paper
Regionalization procedures are used to transfer flood characteristics from gaged to ungaged locations. These procedures are an extension of the gaging network that allows planners and designers to make estimates of flood frequency at ungaged sites of interest. The U.S. Geological Survey has a long time involvement in the development...
Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: A quick, efficient process of igneous differentiation
Rosalind Tuthill Helz, H. Kirschenbaum, J.W. Marinenko
1989, Geological Society of America Bulletin (101) 578-594
Kilauea Iki lava lake, formed in 1959, is a large pond of picritic basalt (average MgO content = 15.34% by weight), which has cooled and crystallized as a small, self-roofed magma chamber. Repeated drilling of the upper crust of the lake, down to its molten core, and more recent (1981)...
Effect of site conditions on ground motion and damage
R. Borcherdt, G. Glassmoyer, M. Andrews, E. Cranswick
1989, Earthquake Spectra (5) 23-42
Results of seismologic studies conducted by the U.S. reconnaissance team in conjunction with Soviet colleagues following the tragic earthquakes of December 7, 1988, suggest that site conditions may have been a major factor in contributing to increased damage levels in Leninakan. As the potential severity of these effects in Leninakan...
Petrologic evolution of divergent peralkaline magmas from the Silent Canyon caldera complex, southwestern Nevada volcanic field
D.A. Sawyer, K. A. Sargent
1989, Journal of Geophysical Research Solid Earth (94) 6021-6040
The Silent Canyon volcanic center consists of a buried Miocene peralkaline caldera complex and outlying peralkaline lava domes. Its location has been corroborated by geophysical data and more than 50 drill holes. Two widespread ash flow sheets, the Tub Spring and overlying Grouse Canyon members of the Miocene Belted Range...
Evidence of uplift near Charleston, South Carolina
S. Rhea
1989, Geology (17) 311-315
In spite of extensive research, the causal structure of the 1886 magnitude 7 earthquake near Charleston, South Carolina, has not been identified. In this study I analyzed digital surface topography and river morphology in light of earlier studies using seismic reflection, seismic refraction,...
