On seismological moments and magnitudes
B. A. Bolt
1991, Earthquakes & Volcanoes (USGS) (22) 111-112
My approach to seismology over the years has always been from the point of view of applied mathematics, as exemplified broadly by the work of the late Sir Harold Jeffreys and Professor K. E. Bullen. Both stresses the development of mathematics in the context of physical systems and of modeling,...
Use of sediment-trace element geochemical models for the identification of local fluvial baseline concentrations
A. J. Horowitz, K. A. Elrick, C. R. Demas, D.K. Demcheck
1991, Conference Paper, IAHS Publication (International Association of Hydrological Sciences)
Studies have demonstrated the utility of fluvial bed sediment chemical data in assesing local water-quality conditions. However, establishing local background trace element levels can be difficult. Reference to published average concentrations or the use of dated cores are often of little use in small areas of diverse local petrology, geology,...
An analytical model for in situ extraction of organic vapors
William R. Roy, R. A. Griffin
1991, Journal of Hazardous Materials (26) 301-317
This paper introduces a simple convective-flow model that can be used as a screening tool and for conducting sensitivity analyses for in situ vapor extraction of organic compounds from porous media. An assumption basic to this model was that the total mass of volatile organic chemicals (VOC) exists in three...
Aerial videotape mapping of coastal geomorphic changes
Karolien Debusschere, Shea Penland, Karen A. Westphal, P. Douglas Reimer, Randolph A. McBride
1991, Conference Paper, Coastal Zone: Proceedings of the Symposium on Coastal and Ocean Management
An aerial geomorphic mapping system was developed to examine the spatial and temporal variability in the coastal geomorphology of Louisiana. Between 1984 and 1990 eleven sequential annual and post-hurricane aerial videotape surveys were flown covering periods of prolonged fair weather, hurricane impacts and subsequent post-storm recoveries. A coastal geomorphic classification...
The significance of Rb-Sr glauconite ages, Bonneterre Formation, Missouri; late Devonian-early Mississippian brine migration in the Midcontinent
H. J. Stein, S.A. Kish
1991, Journal of Geology (99) 468-481
Rb-Sr mean model ages of for glauconites from the Cambrian lower Bonneterre Formation in southern and central Missouri (in contrast to mean model ages of from the middle and upper Bonneterre) are in excellent agreement with...
Paleogeographic implications of an erosional remnant of Paleogene rocks southwest of the Sur-Nacimiento Fault Zone, southern Coast Ranges, California
J. G. Vedder, H. McLean, R. G. Stanley, T. J. Wiley
1991, Geological Society of America Bulletin (103) 941-952
A small tract of heretofore-unrecognized Paleogene rocks lies about 30 km northeast of Santa Maria and 1 km southwest of the Sur-Nacimiento fault zone near upper Pine Creek. This poorly exposed assemblage of rocks is less than 50 m thick, lies unconformably on regionally distributed Upper Cretaceous submarine-fan deposits, and...
Martian paleolakes and waterways: Exobiological implications
D. H. Scott, J. W. Rice Jr., J. M. Dohm
1991, Origins of Life and Evolution of the Biosphere (21) 189-198
The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conductive to the ermergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial...
Publications of the U.S. Geological Survey, 1991
Water Resources Division, U.S. Geological Survey
1991, Report
This catalog is a list of (1) books and maps that were published during 1991, and (2) articles by Geological Survey personnel in non-Geological Survey journals and books that came to our attention in 1991; it supplements the permanent catalogs "Publications of the Geological Survey, 1879-1961", "Publications of the Geological...
Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing
John C. Behrendt, A. Cooper
1991, Geology (19) 315-319
The Cenozoic West Antarctic rift system, characterized by Cenozoic bimodal alkalic volcanic rocks, extends over a largely ice-covered area, from the Ross Sea nearly to the Bellingshausen Sea. Various lines of evidence lead to the following interpretation: the transantarctic Mountains part of the rift shoulder (and probably the entire shoulder)...
Effects of detrital influx in the Pennsylvanian Upper Freeport peat swamp
L.F. Ruppert, R.W. Stanton, C.Blaine Cecil, C.F. Eble, F.T. Dulong
1991, International Journal of Coal Geology (17) 95-116
Quartz cathodoluminescence properties and mineralogy of three sets of samples and vegetal and/ or miospore data from two sets of samples from the Upper Freeport coal bed, west-central Pennsylvania, show that detrital influence from a penecontemporaneous channel is limited to an...
Paleomagnetic constraints on the geometry and timing of deformation at Yucca Mountain, Nevada
J. G. Rosenbaum, M.R. Hudson, R. B. Scott
1991, Journal of Geophysical Research (96) 1963-1979
Paleomagnetic data from Miocene ash flow sheets indicate that southern Yucca Mountain has undergone about 30° of clockwise vertical-axis rotation since emplacement of the Tiva Canyon Member of the Paintbrush Tuff at about 13 Ma. Declinations of remanent magnetization from 32 sites in the reversely...
Control of pest species: Tree shelters help protect seedlings from nutria
J. A. Allen, R. Boykin
1991, Restoration & Management Notes (9) 122-124
Various methods of nutria preventative techniques were tested in attempts to curb the loss of seedlings due to nutria capturing. The results of testing possibly indicate that tree shelters have real potential for use in forest restoration projects on sites with moderate nutria populations. Tree shelters may even prove effective...
Landscape analysis: Theoretical considerations and practical needs
A.E. Godfrey, E.T. Cleaves
1991, Environmental Geology and Water Sciences (17) 141-155
Numerous systems of land classification have been proposed. Most have led directly to or have been driven by an author's philosophy of earth-forming processes. However, the practical need of classifying land for planning and management purposes requires that a system lead to predictions of the results of management activities. We...
Prospecting for zones of contaminated ground-water discharge to streams using bottom-sediment gas bubbles
Don A. Vroblesky, Michelle M. Lorah
1991, Groundwater (29) 333-340
Decomposition of organic-rich bottom sediment in a tidal creek in Maryland results in production of gas bubbles in the bottom sediment during summer and fall. In areas where volatile organic contaminants discharge from ground water, through the bottom sediment, and into the creek, part of the volatile contamination diffuses into...
Lower Paleozoic rock units in the Osgood Mountains and surrounding areas, and the Golconda thrust fault, Humboldt County, north-central Nevada
D. J. Madden-McGuire
1991, Book chapter, Geology and ore deposits of the Great Basin; field trip guidebook compendium
No abstract available ...
Structure, stratigraphy, and mineralization of the upper plate of the Bullfrog Hills detach ment fault system, Bullfrog Hills area, with emphasis on the geology of Bullfrog Mountain, Nye County, southern Nevada
Florian Maldonado
1991, Book chapter, Geology and ore deposits of the Great Basin; field trip guidebook compendium
No abstract available ...
Is the extent of glaciation limited by marine gas-hydrates?
Charles K. Paull, William Ussler III, William P. Dillon
1991, Geophysical Research Letters (18) 432-434
Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming [Revelle, 1983; Kvenvolden, 1988a; Nisbet, 1990]. We...
Use of stable isotopes, tritium, soluble salts, and redox-sensitive elements to distinguish ground water from irrigation water in the Salton Sea basin
Roy A. Schroeder, James G. Setmire, Jill N. Densmore
1991, Conference Paper
Evaporative concentration of irrigation water diverted from the Colorado River to the Salton Sea basin for several decades has produced an overlying system (that includes drainwater and surface waters) whose composition is highly variable and differs from that of the shallow regional ground water beneath it. The role of hydrologic...
Observation of suspended sediments in Mobile Bay, Alabama from satellite
Richard P. Stumpf
1991, Conference Paper, Coastal Sediments '91
As part of a comprehensive geologic study of coastal Alabama and Mississippi, the U.S. Geological Survey is investigating coastal sediment transport in Mobile Bay and the adjacent shelf. Satellite imagery from the NOAA AVHRR is being used to provide data on the variability of spatial patterns in the near-surface suspended...
Climate Divisions
National Climatic Data Center
1991, Report
This is a coverage of climate divisions from the National Climatic Data Center....
Solution of the one-dimensional consolidation theory equation with a pseudospectral method
N. Sepulveda
Anon, editor(s)
1991, Conference Paper, IAHS Publication (International Association of Hydrological Sciences)
The one-dimensional consolidation theory equation is solved for an aquifer system using a pseudospectral method. The spatial derivatives are computed using Fast Fourier Transforms and the time derivative is solved using a fourth-order Runge-Kutta scheme. The computer model calculates compaction based on the void ratio changes accumulated during the simulated...
First early Mesozoic amber in the Western Hemisphere
R. J. Litwin, S.R. Ash
1991, Geology (19) 273-276
Detrital amber pebbles and granules have been discovered in Upper Triassic strata on the Colorado Plateau. Although amber pre-viously has been reported from Pennsylvanian, Jurassic, Cretaceous, and Tertiary strata, we know of no other reported Triassic occurrence in North America or the Western...
Volcanologists and the geologic past
D. A. Swanson
1991, Earthquakes & Volcanoes (USGS) (22) 138-139
Were volcanologists to be asked why they study active volcanoes, they would list many reasons: to understand their dynamics, to use them as windows into the earth, to warn of hazards, to provide nearly real-time information on rates of various physical and chemical processes, and many others. Near the bottom...
The tholeiite to alkalic basalt transition at Haleakala Volcano, Maui, Hawaii
C.-Y. Chen, F.A. Frey, M.O. Garcia, G. B. Dalrymple, S.R. Hart
1991, Contributions to Mineralogy and Petrology (106) 183-200
Previous studies of alkalic lavas erupted during the waning growth stages (<0.9 Ma to present) of Haleakala volcano identified systematic temporal changes in isotopic and incompatible element abundance ratios. These geochemical trends reflect a mantle mixing process with a systematic change in the proportions of mixing...
A geological assessment of shoreline erosion, U.S. Great Lakes
D. W. Folger
1991, Conference Paper, Geological hazards: Proceedings of Beijing International Symposium
No abstract available....
