Evolution of the Precambrian lithosphere: Seismological and geochemical constraints
R. Durrheim, Walter D. Mooney
1994, Journal of Geophysical Research B: Solid Earth (99) 15359-15374
Several recent models of crustal evolution are based on the belief that the thickness of the continental crust is proportional to its age, with ancient crust being the thickest. A worldwide review of seismic structure contradicts this belief and falsifies these models, at least for the Archean....
Bed material and numerical modeling in a gravel/cobble stream
Robert T. Milhous, R. Dodge, P. Johnson
1994, Book, Proceedings of the American Society of Civil Engineers Conference
No abstract available....
Crustal velocity structure of the northern Yukon-Tanana upland, central Alaska: Results from TACT refraction/wide-angle reflection data
Bruce C. Beaudoin, Gary S. Fuis, William J. Lutter, Walter D. Mooney, Thomas E. Moore
1994, Bulletin (106) 981-1001
The Fairbanks North seismic refraction/ wide-angle reflection profile, collected by the U.S. Geological Survey Trans-Alaska Crustal Transect (TACT) project in 1987, crosses the complex region between the Yukon-Tanana and Ruby terranes in interior Alaska. This region is occupied by numerous small terranes elongated in a northeast-southwest direction. These seismic data...
An image of the Columbia Plateau from inversion of high‐resolution seismic data
William J. Lutter, Rufus D. Catchings, Craig M. Jarchow
1994, Geophysics (59) 1278-1289
We use a method of traveltime inversion of high‐resolution seismic data to provide the first reliable images of internal details of the Columbia River Basalt Group (CRBG), the subsurface basalt/sediment interface, and the deeper sediment/basement interface. Velocity structure within the basalts, delineated on the order of 1 km horizontally and...
Dynamic growth of mixed-mode shear cracks
D.J. Andrews
1994, Bulletin of the Seismological Society of America (84) 1184-1198
A pure mode II (in-plane) shear crack cannot propagate spontaneously at a speed between the Rayleigh and S-wave speeds, but a three-dimensional (3D) or two-dimensional (2D) mixed-mode shear crack can propagate in this range, being driven by the mode III (antiplane) component. Two different analytic solutions have been proposed for...
The seismic velocity structure of the Newfoundland Appalachian orogen
Stephen Hughes, Jeremy Hall, James H. Luetgert
1994, Journal of Geophysical Research B: Solid Earth (99) 13633-13653
The deep structure of the Newfoundland Appalachian orogen is investigated by analyses of three intersecting seismic refraction/wide-angle reflection profiles which traverse the Gander and Dunnage zones or central mobile belt of Newfoundland. A simultaneous travel time inversion for velocity and interface was applied to the in-line seismic refraction/wide-angle reflection data...
Diagenesis of diatomite from the Kolubara Coal Basin, Baroševac, Serbia
J. Obradovic, James R. Hein, J. Djurdjevic
1994, Geological Journal (29) 209-217
Diatomite associated with the Kolubara Coal Basin was studied to better understand early stage silica diagenesis of shallow water deposits. The Kolubara Basin consists of Neogene siliciclastic rocks, diatomite, marlstone and rare carbonates. Palaeozoic metamorphic and Mesozoic sedimentary and igneous basement rocks are transgressively overlain by Upper Miocene sandstone, siltstone,...
Climate, soil water storage, and the average annual water balance
P. C. D. Milly
1994, Water Resources Research (30) 2143-2156
This paper describes the development and testing of the hypothesis that the long-term water balance is determined only by the local interaction of fluctuating water supply (precipitation) and demand (potential evapotranspiration), mediated by water storage in the soil. Adoption of this hypothesis, together with idealized representations of relevant input variabilities...
Geochemical interactions between constituents in acidic groundwater and alluvium in an aquifer near Globe, Arizona
Kenneth G. Stollenwerk
1994, Applied Geochemistry (9) 353-369
Acidic water from a copper-mining area has contaminated an alluvial aquifer and stream near Globe, Arizona. The most contaminated groundwater has a pH of 3.3, and contains about 100 mmol/1 SO4, 50 mmol/1 Fe, 11 mmol/1 Al and 3 mmol/1 Cu. Reactions between alluvium and acidic groundwater were first evaluated...
Aquatic invertebrate production in southeastern USA wetlands during winter and spring
Walter G. Duffy, Douglas LaBar
1994, Wetlands (14) 88-97
We measured aquatic invertebrate abundance, standing stock biomass, and community production in three types of wetlands on Noxubee National Wildlife Refuge from December 1987 through April 1988. Together, Orthocyclops modestus and Daphnia pulex were the most abundant organisms collected in all habitats during both winter and spring, but each contributed little to total standing...
Gravity survey of the Mount Toondina impact structure, South Australia
J. B. Plescia, Eugene Merle Shoemaker, Carolyn S. Shoemaker
1994, Journal of Geophysical Research E: Planets (99) 13167-13179
Gravity and seismic reflection data, together with geologic mapping, indicate that the Mount Toondina feature in South Australia is best interpreted as an eroded 4-km-diameter impact structure consisting of a ring structural depression surrounding a pronounced central uplift. Beds at the center of the structure within the...
Hydrogeology, simulation of regional ground-water flow, and saltwater intrusion, Potomac-Raritan-Magothy Aquifer System, Northern Coastal Plain of New Jersey
Amleto A. Pucci Jr., Daryll A. Pope, JoAnn M. Gronberg
1994, New Jersey Geological Survey Report 36
The Potomac-Raritan-Magothy aquifer system in Middlesex and Monmouth Counties in the northern Coastal Plain of New Jersey consists primarily of unconsolidated Cretaceous sediments, which are divided into the upper and middle aquifers and confining units. These units, which strike northeastsouthwest along the Fall Line, dip and thicken to the southeast....
Seismic guided waves trapped in the fault zone of the Landers, California, earthquake of 1992
Keiiti Aki, David L. Adams, Akiko Hasemi, W.H.K. Lee
1994, Journal of Geophysical Research B: Solid Earth (99) 11705-11722
A mobile seismic array of seven stations was deployed at 11 sites along the fault trace of the M7.4 Landers earthquake of June 28, 1992, with a maximum offset of 1 km from the trace. We found a distinct wave train with a relatively long period following the S waves...
Habitat use by an endangered riverine fish and implications for species protection
B. J. Freeman, Mary C. Freeman
1994, Ecology of Freshwater Fish (3) 49-58
We investigated habitat specificity of the amber darter (Percina antesella Williams & Etnier 1977), an imperiled fish from restricted portions of 2 rivers in the southeastern United States. Foraging amber darters occupied a narrow range of riffle habitat, consistently avoiding areas < 20 cm deep and with velocity < 10 cm....
CASERTZ aeromagnetic data reveal late Cenozoic flood basalts(?) in the West Antarctic rift system
John C. Behrendt, D. D. Blankenship, Carol A. Finn, Robin E. Bell, Ronald E. Sweeney, Steven M. Hodge, John M. Brozena
1994, Geology (22) 527-530
The late Cenozoic volcanic and tectonic activity of the enigmatic West Antarctic rift system, the least understood of the great active continental rifts, has been suggested to be plume driven. In 1991-1992, as part of the CASERTZ (Corridor Aerogeophysics of the Southeast Ross Transect Zone) program, an ∼25000 km aeromagnetic...
Petrogenesis of the highly potassic 1.42 Ga Barrel Spring pluton, southeastern California, with implications for mid-Proterozoic magma genesis in the southwestern USA
James D. Gleason, Calvin F. Miller, J. L. Wooden, Victoria C. Bennett
I. S. E. Carmichael, editor(s)
1994, Contributions to Mineralogy and Petrology (118) 182-197
Syenites from the Barrel Spring pluton were emplaced in the Early Proterozoic Mojave crustal provine of southeastern California at 1.42 Ga. All rocks, even the most mafic, are highly enriched in incompatible elements (e.g. K2O 4–12 wt%, Rb 170–370 ppm, Th 12–120 ppm, La 350–1500xchondrite, La/Ybn 35–100)....
Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone
S. E. Hough, Y. Ben-Zion, P. Leary
1994, Bulletin of the Seismological Society of America (84) 761-767
Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of:...
Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake
M.J.S. Johnston, A. T. Linde, D.C. Agnew
1994, Bulletin of the Seismological Society of America (84) 799-805
High-precision strain was observed with a borehole dilational strainmeter in the Devil's Punchbowl during the 11:58 UT 28 June 1992 MW 7.3 Landers earthquake and the large Big Bear aftershock (MW 6.3). The strainmeter is installed at a depth of 176 m in the fault zone approximately midway between...
Local observations of the onset of a large earthquake: 28 June 1992 Landers, California
Richael Abercrombie, Jim Mori
1994, Bulletin of the Seismological Society of America (84) 725-734
The Landers earthquake (MW 7.3) of 28 June 1992 had a very emergent onset. The first large amplitude arrivals are delayed by about 3 sec with respect to the origin time, and are preceded by smaller-scale slip. Other large earthquakes have been observed to have similar emergent onsets, but the...
Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake
M. J. Johnston, R.J. Mueller, Yoichi Sasai
1994, Bulletin of the Seismological Society of America (84) 792-798
Recent reports suggest that large magnetic field changes occur prior to, and during, large earthquakes. Two continuously operating proton magnetometers, LSBM and OCHM, at distances of 17.3 and 24.2 km, respectively, from the epicenter of the 28 June 1992 Mw 7.3 Landers earthquake, recorded data through the earthquake...
Foreshocks, aftershocks, and earthquake probabilities: Accounting for the landers earthquake
Lucile M. Jones
1994, Bulletin of the Seismological Society of America (84) 892-899
The equation to determine the probability that an earthquake occurring near a major fault will be a foreshock to a mainshock on that fault is modified to include the case of aftershocks to a previous earthquake occurring near the fault. The addition of aftershocks to the background seismicity makes its...
Triggered seismicity and deformation between the Landers, California, and Little Skull Mountain, Nevada, earthquakes
Paul Bodin, Joan Gomberg
1994, Bulletin of the Seismological Society of America (84) 835-843
This article presents evidence for the channeling of strain energy released by the Ms = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in seismicity levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the...
The co-seismic slip distribution of the Landers earthquake
J. Freymueller, N.E. King, P. Segall
1994, Bulletin of the Seismological Society of America (84) 646-659
We derived a model for the co-seismic slip distribution on the faults which ruptured during the Landers earthquake sequence of 28 June 1992. The model is based on the inversion of surface geodetic measurements, primarily vector displacements measured using the Global Positioning System (GPS). The inversion procedure assumes...
Dense array recordings in the San Bernardino Valley of landers-big bear aftershocks: Basin surface waves, Moho reflections, and three-dimensional simulations
Arthur Frankel
1994, Bulletin of the Seismological Society of America (84) 613-624
Fourteen GEOS seismic recorders were deployed in the San Bernardino Valley to study the propagation of short-period (T ≈ 1 to 3 sec) surface waves and Moho reflections. Three dense arrays were used to determine the direction and speed of propagation of arrivals in the seismograms. The seismograms for...
Triggering of the Ms = 5.4 Little Skull Mountain, Nevada, earthquake with dynamic strains
Joan Gomberg, Paul Bodin
1994, Bulletin of the Seismological Society of America (84) 844-853
We have developed an approach to test the viability of dynamic strains as a triggering mechanism by quantifying the dynamic strain tensor at seismogenic depths. We focus on the dynamic strains at the hypocenter of the Ms = 5.4 Little Skull Mountain (LSM), Nevada, earthquake. This event is noteworthy...
