Sedimentology and cyclicity in the Lower Permian De Chelly Sandstone on the Defiance Plateau: Eastern Arizona
J. D. Stanesco
1991, Mountain Geologist (28) 1-11
The Lower Permian (Leonardian) De Chelly Sandstone crops out along a north-south trend on the Defiance Plateau of eastern Arizona. It is divided into lower and upper members separated by a tongue of the Supai Formation that pinches out to the north.Lithofacies in the De Chelly Sandstone consist of (1)...
Pre-exploitation state of the Ahuachapán geothermal field, El Salvador
Z. Aunzo, C. Laky, B. Steingrimsson, G.S. Bodvarsson, M.J. Lippmann, A.H. Truesdell, C. Escobar, A. Quintanilla, G. Cuellar
1991, Geothermics (20) 1-22
The lithology and structural features of the Ahuachapán geothermal area and their impact on the movement of cold and hot fluids within the system are described, as well as the development and evaluation of the natural state model of the field. Four major lithologic units are present in Ahuachapán and...
Herbicides in surface waters of the midwestern United States: The effect of spring flush
E.M. Thurman, D. A. Goolsby, M. T. Meyer, D.W. Kolpin
1991, Environmental Science & Technology (25) 1794-1796
Approximately three-fourths of all preemergent herbicides used in the United States are applied to row crops over a 12-state area, called the "corn belt" (I). The application of these compounds may cause widespread degradation of water quality (2). Because herbicides are water soluble, there is the potential for leaching into...
Commentary on the sphalerite geobarometer
P. Toulmin III, P. B. Barton Jr., L.B. Wiggins
1991, American Mineralogist (76) 1038-1051
The FeS content of sphalerite in assemblages with pyrite and pyrrhotite has been widely used and widely criticized as a geobarometer. The commonly accepted form of the geobarometer is based on the composition of sphalerite being independent of temperature below about 550??C at all pressures up to at least 10...
Late Cretaceous and early Tertiary plutonism and deformation in the Skagit Gneiss Complex, north Cascade Range, Washington and British Columbia
R. A. Haugerud, P. Van Der Heyden, R. W. Tabor, J. S. Stacey, R. E. Zartman
1991, Geological Society of America Bulletin (103) 1297-1307
The Skagit Gneiss Complex forms a more-or-less continuous terrane within the northern, more deeply eroded part of the North Cascade Range. The complex comprises abundant plutons intruded at mid-crustal depths into a variety of metamorphosed supracrustal rocks of both oceanic and volcanic-arc origin. A plethora of syntectonic pegmatite, small plutons,...
Organic petrology of epi-impsonite at Page, Oklahoma, U.S.A.
Brian J. Cardott
1991, Organic Geochemistry (17) 185-191
Impsonite (asphaltic pyrobitumen) occurs as fracture-filling veins cutting massive sandstone in the frontal Ouachita Mountains near Page, Oklahoma. The Page impsonite formed from low-temperature alteration of crude oil. Mean maximum bitumen reflectance in oil immersion (Rmax">Rmax) of seven samples is 1.41–1.96%. Mean apparent bireflectance...
Fault orientations in extensional and conjugate strike-slip environments and their implications
W. Thatcher, D.P. Hill
1991, Geology (19) 1116-1120
Seismically active conjugate strike-slip faults in California and Japan typically have mutually orthogonal right- and left-lateral fault planes. Normal- fault dips at earthquake nucleation depths are concentrated between 40° and 50°. The observed orientations and their strong clustering are surprising, because conventional faulting...
Crustal resistivity structure from magnetotelluric soundings in the Colorado Plateau-Basin and Range provinces, central and western Arizona
D. P. Klein
1991, Journal of Geophysical Research (96) 12313-12331
Resistivity structure to about 25 km depth is defined from two-dimensional modeling of 29 magnetotelluric (MT) soundings (0.002–5 Hz) that traverse 280 km of the southwestern Colorado Plateau, transition zone, and Basin and Range provinces in Arizona. From the surface to 5 km depth, the MT...
Estimation of suspended-sediment rating curves and mean suspended-sediment loads
Charles G. Crawford
1991, Journal of Hydrology (129) 331-348
Suspended-sediment loads are often estimated from an empirical relation between suspended-sediment load (L) and streamflow (S). This relation is usually defined as a power function, L = aSh, and is referred to as a suspended-sediment rating curve. This function can be formulated as either a linear or non-linear model to...
Convergent radial dispersion: A note on evaluation of the Laplace transform solution
Allen F. Moench
1991, Water Resources Research (27) 3261-3264
A numerical inversion algorithm for Laplace transforms that is capable of handling rapid changes in the computed function is applied to the Laplace transform solution to the problem of convergent radial dispersion in a homogeneous aquifer. Prior attempts by the author to invert this solution were unsuccessful for highly advective...
Satellite and earth science data management activities at the U.S. geological survey's EROS data center
David M. Carneggie, Gary G. Metz, William C. Draeger, Ralph J. Thompson
1991, Conference Paper, GIS/LIS 1991 ACSM-ASPRS Fall Convention
The U.S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center, the national archive for Landsat data, has 20 years of experience in acquiring, archiving, processing, and distributing Landsat and earth science data. The Center is expanding its satellite and earth science data management activities to support the U.S. Global...
Quantitative controls on submarine slope failure morphology
H.J. Lee, W. C. Schwab, B. D. Edwards, R. E. Kayen
1991, Marine Geotechnology (10) 143-157
The concept of the steady-state of deformation can be applied to predicting the ultimate form a landslide will take. The steady-state condition, defined by a line in void ratio-effective stress space, exists at large levels of strain and remolding. Conceptually, if sediment initially exists with void ratio-effective stress conditions above...
Flexural extension of the upper continental crust in collisional foredeeps
D. C. Bradley, W.S.F. Kidd
1991, Geological Society of America Bulletin (103) 1416-1438
Normal faults on the outer slopes of trenches and collisional foredeeps reveal that high-amplitude lithospheric flexure can result in inelastic extensional deformation of the convex side of a flexed plate. This process, which we call "flexural extension," differs fundamentally from rifting in that...
Suggestions to authors of the reports of the United States Geological Survey
Wallace R. Hansen, editor(s)
1991, Report
Suggestions to Authors (STA) is used as the writing style guide for the U.S. Geological Survey (USGS) technical reports and maps. The STA is widely distributed in paper outside of the USGS as a basic scientific writing style guide for scientists, students, and editors. The goal of STA is to...
Prospecting for gold in the United States
Harold Kirkemo
1991, Report
Our changing continent
John Stevens Schlee
1991, Report
U.S. Geological Survey: earth science in the public service
Water Resources Division, U.S. Geological Survey
1991, Report
No abstract available....
Chemicals for worldwide aquaculture
R. A. Schnick
1991, Book chapter, Fish health management in Asia-Pacific: report on a regional study and workshop on fish disease and fish health management
Regulations and therapeutants or other safe chemicals that are approved or acceptable for use in the aquaculture industry in the US, Canada, Europe and Japan are presented, discussing also compounds that are unacceptable for aquaculture. Chemical use practices that could affect public health are considered and details given regarding efforts...
A Lome Prieta experience
Thomas C. Hanks
1991, Earthquakes & Volcanoes (USGS) (22) 124-128
Relationship between weathered coal deposits and the etiology of Balkan endemic nephropathy
G. L. Feder, Z. Radovanovic, R. B. Finkelman
1991, Conference Paper, Kidney International
Field studies in epidemiology and environmental geochemistry in areas in Yugoslavia containing villages with a high incidence of Balkan endemic nephropathy (BEN), indicate a possible relationship between the presence of low-rank coal deposits and the etiology of BEN. Preliminary results from qualitative chemical analyses of drinking water from shallow farm...
Near-real-time mosaics from high-resolution side-scan sonar
William W. Danforth, Thomas F. O’Brien, W. C. Schwab
1991, Sea Technology (32) 54-59
High-resolution side-scan sonar has proven to be a very effective tool for stuyding and understanding the surficial geology of the seafloor. Since the mid-1970s, the US Geological Survey has used high-resolution side-scan sonar systems for mapping various areas of the continental shelf. However, two problems typically encountered included the short...
Herbicides in streams. Midwestern United States
Donald A. Goolsby, E. Michael Thurman, Dana W. Kolpin
1991, Conference Paper
Results from a 2-year study of 149 streams geographically distributed across the corn-producing region of 10 midwestern States show that detectable concentrations of herbicides persist year round in most streams. Some herbicides exceeded proposed maximum contaminant levels for drinking water for periods of several weeks to several months following application....
U-series dating of impure carbonates: An isochron technique using total-sample dissolution
J. L. Bischoff, J.A. Fitzpatrick
1991, Geochimica et Cosmochimica Acta (55) 543-554
U-series dating is a well-established technique for age determination of Late Quaternary carbonates. Materials of sufficient purity for nominal dating, however, are not as common as materials with mechanically inseparable aluminosilicate detritus. Detritus contaminates the sample with extraneous Th. We propose that correction for contamination is best accomplished with the...
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...
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,...
