Occurrence, distributions, and transport of herbicides and their degradation products in the lower Mississippi river and its tributaries
W. E. Pereira
1990, ES and T Contents (24) 1400-1406
The Mississippi River and its tributaries drain extensive agricultural regions of the midcontinental United States, where large amounts of herbicides are applied as weed control agents on crops such as corn and soybeans. Studies being conducted by the U.S. Geological Survey along the lower Mississippi River and its major tributaries,...
Sedimentology and petroleum occurrence, Schoolhouse Member, Maroon Formation (Lower Permian), northwestern Colorado
Samuel Y. Johnson, Christopher J. Schenk, D. L. Anders, Michele L. Tuttle
1990, American Association of Petroleum Geologists Bulletin (74) 135-150
The Lower Permian Schoolhouse Member of the Maroon Formation forms a partly exhumed petroleum reservoir in the Eagle basin of northwestern Colorado. The Schoolhouse consists mainly of yellowish gray to gray, low-angle to parallel bedded, very fine to fine-grained sandstone of eolian sand-sheet origin; interbedded fluvial deposits are present in...
Age of the Peach Springs Tuff, southeastern California and western Arizona
J. E. Nielson, D. R. Lux, G. B. Dalrymple, A. F. Glazner
1990, Journal of Geophysical Research Solid Earth (95) 571-580
Sanidine separates from pumice of the early Miocene Peach Springs Tuff are concordantly dated at 18.5±0.2 Ma by two isotopic techniques. The Peach Springs Tuff is the only known unit that can be correlated between isolated outcrops of Miocene strata from the central Mojave Desert of southeastern California to the...
H2O grain size and the amount of dust in Mars' residual North polar cap
H. H. Kieffer
1990, Journal of Geophysical Research (95) 1481-1493
In Mars' north polar cap the probable composition of material residual from the annual condensation cycle is a mixture of fine dust and H2O grains of comparable size and abundance. However, metamorphism of such material will gradually lower its albedo by increasing the size of the H2O grains only. If...
Sediment movement along the U.S. east coast continental shelf-I. Estimates of bottom stress using the Grant-Madsen model and near-bottom wave and current measurements
V.D. Lyne, B. Butman, W.D. Grant
1990, Continental Shelf Research (10) 397-428
Bottom stress is calculated for several long-term time-series observations, made on the U.S. east coast continental shelf during winter, using the wave-current interaction and moveable bed models of Grant and Madsen (1979, Journal of Geophysical Research, 84, 1797-1808; 1982, Journal of Geophysical Research, 87, 469-482). The wave and current measurements...
Multi-model stereo restitution
K.S. Dueholm
1990, Photogrammetric Engineering and Remote Sensing (56) 239-242
Methods are described that permit simultaneous orientation of many small-frame photogrammetric models in an analytical plotter. The multi-model software program enables the operator to move freely between the oriented models during interpretation and mapping. Models change automatically when the measuring mark is moved from one frame to another, moving to...
A tomographic glimpse of the upper mantle source of magmas of the Jemez lineament, New Mexico
W. Spence, R.S. Gross
1990, Journal of Geophysical Research Solid Earth (95) 10829-10849
The 800-km-long Jemez lineament is the most active volcanic feature in the southwestern United States. It is the southeastern tectonic boundary of the Colorado Plateau and crosses the Rio Grande rift at the Jemez Mountains. The primary volcanism of the lineament is basaltic and has occurred in the last 4.5...
Measurement and interpretation of low levels of dissolved oxygen in ground water
A. F. White, M. L. Peterson, R.D. Solbau
1990, Groundwater (28) 584-590
A Rhodazine-D colorimetric technique was adapted to measure low-level dissolved oxygen concentrations in ground water. Prepared samples containing between 0 and 8.0 μmoles · 1-1 dissolved oxygen in equilibrium with known gas mixtures produced linear spectrophotometric absorbance with a lower detection limit of 0.2 μmoles ·...
Soil development on stable landforms and implications for landscape studies
J.W. Harden
1990, Geomorphology (3) 391-398
Soil development parameters include a wide variety of morphological, chemical, and mineralogical parameters, but some of the best indicators of time and surface stability are derived from field morphology. Over long time-spans, the most common time function for soil development is exponential...
Calculation of zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an elastic half-space
Hsi-Ping Liu
1990, Bulletin of the Seismological Society of America (80) 832-856
Impulse responses including near-field terms have been obtained in closed form for the zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an anelastic half-space. The method is based on the correspondence principle. Through transformation of variables, the Fourier transform of the elastic impulse...
Radiocarbon analyses from Cincinnati, Ohio, and their implications for glacial stratigraphic interpretations
T.V. Lowell, K.M. Savage, Brockman C. Scott, R. Stuckenrath
1990, Quaternary Research (34) 1-11
Detailed analysis of a site near Cincinnati, Ohio, shows that 14C ages of samples in a single geologic unit can have a range of several thousand years and ages from different stratigraphic units can overlap. At the Sharonville site, four 14C samples from organic silt below glaciogenic deposits have an...
Source parameters for small events associated with the 1986 North Palm Springs, California, earthquake determined using empirical Green functions
J. Mori, A. Frankel
1990, Bulletin of the Seismological Society of America (80) 278-295
Using small events as empirical Green functions, which include path, site, and instrument effects on the P waveforms, source parameters were estimated for 25 ML 3.4 to 4.4 events associated with the 1986 North Palm Springs earthquake. The static stress drops ranged from 3 to 80 bars, for moments of...
The modernization program of the US Geological Survey's National Mapping Division
Kirk E. Anderson, G.M. Callahan
1990, Cartography and Geographic Information Systems (17) 243-248
Discusses the components of the National Digital Cartographic Data Base of the USA, to be completed by the year 2000. Key tasks are; expand the digitising programme; modify data structures; develop digital revision capabilities; develop and adopt standards and implement quality control; support advanced analysis. -after Authors...
Earthquake and volcano hazard notices: An economic evaluation of changes in risk perceptions
R. L. Bernknopf, D.S. Brookshire, M.A. Thayer
1990, Journal of Environmental Economics and Management (18) 35-49
Earthquake and volcano hazard notices were issued for the Mammoth Lakes, California area by the U.S. Geological Survey under the authority granted by the Disaster Relief Act of 1974. The effects on investment, recretion visitation, and risk perceptionsare explored.The hazard notices did not affect recreation visitation, although investment was affected....
Pedologic and climatic controls on Rn-222 concentrations in soil gas, Denver, Colorado
S. Asher-Bolinder, D.E. Owen, R.R. Schumann
1990, Geophysical Research Letters (17) 825-828
Soil-gas radon concentrations are controlled seasonally by factors of climate and pedology. In a swelling soil of the semiarid Western United States, soil-gas radon concentrations at 100 cm depth increase in winter and spring due to increased emanation with higher soil moisture and the capping effect...
The flaminio obelisk in Rome: vibrational characteristics as part of preservation efforts
G. Bongiovanni, M. Çelebi, P. Clemente
1990, Earthquake Engineering and Structural Dynamics (19) 107-118
The purpose of the paper is to study the vibrational characteristics of the Flaminio Obelisk in Rome as part of general studies being performed for preservation purposes. The state of preservation of the monument is described as well as the sonic method used to evaluate the integrity of the sections....
Heat capacities and thermodynamic properties of annite (aluminous iron biotite)
B. S. Hemingway, R. A. Robie
1990, American Mineralogist (75) 183-187
The heat capacities have been measured between 7 and 650 K by quasi-adiabatic calorimetry and differential scanning calorimetry. At 298.15 K and 1 bar, the calorimetric entropy for our sample is 354.9??0.7 J/(mol.K). A minimum configurational entropy of 18.7 J/(mol.K) for full disorder of Al/Si in the tetrahedral sites should...
Chemistry and origin of minor and trace elements in selected vitrinite concentrates from bituminous and anthracitic coals
C.A. Palmer, P.C. Lyons
1990, International Journal of Coal Geology (16) 189-192
Organic and inorganic affinities were determined by comparing the elemental concentrations in the vitrinite concentrates to the concentrations in the companion whole coals. The ratios of these concentrations for 33 selected elements are shown in Figure 1. Ratios greater than 1...
Effects of elevated temperatures and rising sea level on Arctic Coast
Peter W. Barnes
1990, Journal of Cold Regions Engineering (4) 21-28
Ice is a major agent on the inner shelf, gouging the bottom, increasing hydraulic scour, transporting sediment, and influencing river flood patterns. Rapid coastal retreat is common and low barrier islands and beaches are constantly changing due to the influence of permafrost, ice‐push, waves, and currents. Coastal processes are presently...
Sediment thickness in the southern Canada Basin
S. D. May, A. Grantz
1990, Marine Geology (93) 331-347
Multichannel seismic reflection data are used, in conjunction with deep crustal seismic refraction data, to estimate the thickness of sediments in the southern Canada Basin of the Arctic Ocean north of Alaska. The sediments are interpreted to be of Hauterivian (mid-Early Cretaceous)...
A quantitative micropaleontologic method for shallow marine peleoclimatology: Application to Pliocene deposits of the western North Atlantic Ocean
T. M. Cronin, H.J. Dowsett
1990, Marine Micropaleontology (16) 117-147
A transfer function was developed to estimate summer and winter paleotemperatures for arctic to tropical regions of the western North Atlantic Ocean using fossil ostracode assemblages. Q-mode factor analysis was run on ostracode assemblages from 100 modern bottom sediment samples from continental shelves of North America, Greenland and the Caribbean...
Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa
E. Arthur Bettis III, R. G. Baker, B.K. Nations, D.W. Benn
1990, Quaternary Research (33) 102-107
A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ?? 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench...
Age determinations and growth rates of Pacific ferromanganese deposits using strontium isotopes
B.L. Ingram, J.R. Hein, G. L. Farmer
1990, Geochimica et Cosmochimica Acta (54) 1709-1721
87Sr 86Sr ratios, trace element and REE compositions, and textural characteristics were determined for three hydrogenetic Fe-Mn crusts, one hydrothermal deposit, and two mixed hydrothermalhydrogenetic crusts from the Pacific. The Sr isotope data are compared to the Sr seawater curve for the Cenozoic to determine the ages and growth rates...
The initial instability and finite-amplitude stability of alternate bars in straight channels
Jonathan M. Nelson
1990, Earth-Science Reviews (29) 97-115
The initial instability and fully developed stability of alternate bars in straight channels are investigated using linearized and nonlinear analyses. The fundamental instability leading to these features is identified through a linear stability analysis of the equations governing the flow and sediment transport fields. This instability is explained in terms...
Chronologic and isotopic framework for early Proterozoic crustal evolution in the eastern Mojave Desert region, SE California
J. L. Wooden, D. M. Miller
1990, Journal of Geophysical Research (95) 20133-20146
The Early Proterozoic geologic evolution of the eastern Mojave Desert region, as defined by characteristics of its supracrustal rocks, granitoids, metamorphism, structural history, and Pb and Nd isotopic signature, contrasts sharply with other Proterozoic provinces of the southwestern United States. The oldest supracrustal rocks of the Mojave Desert region contain...
