Incorporation of rare earth elements in titanite: Stabilization of the A2/a dimorph by creation of antiphase boundaries
J.M. Hughes, E.S. Bloodaxe, J.M. Hanchar, E.E. Foord
1997, American Mineralogist (82) 512-516
The atomic arrangement of a natural rare-earth-rich titanite and two synthetic rare-earth-doped titanites have been refined in space group A2/a, and the atomic arrangement of an undoped P21/a synthetic titanite was also refined for comparison. Previous work has shown that titanite possesses a domain structure, with domains formed of like-displaced...
Sequential cavity use in a cottonwood bottomland
J.A. Sedgwick
1997, Condor (99) 880-887
I studied the patterns and frequency of cavity reuse in a community of cavity-nesting birds in a cottonwood bottomland along the South Platte River in northeastern Colorado from 1985-1987. Of 100 cavities occupied in 1985, 56% were mused in 1986; 38.5% of 122 cavities occupied in 1986 were mused in...
Didymoceras puebloense, a new species of heteromorph ammonite from the Upper Campanian of Colorado and Wyoming
W. A. Cobban, W. J. Kennedy, G. R. Scott
1997, Geobios (30) 225-230
Didymoceras puebloense nov. sp. is described from the upper Campanian zones of Didymoceras nebrascense and Didymoceras stevensoni in Pueblo and Pitkin Counties, Colorado, and Weston County, Wyoming in the United States Western Interior. The species is characterized by a middle helical growth stage in which the succesive whorls are widely separated followed by a...
A mechanism for high wall-rock velocities in rockbursts
Art McGarr
1997, Pure and Applied Geophysics (150) 381-391
Considerable evidence has been reported for wall-rock velocities during rockbursts in deep gold mines that are substantially greater than ground velocities associated with the primary seismic events. Whereas varied evidence suggests that slip across a fault at the source of an event generates nearby particle velocities of, at most, several...
Latitudinal distribution of O2on ganymede: Observations with the hubble space telescope
W. M. Calvin, J.R. Spencer
1997, Icarus (130) 505-516
To help constrain the spatial variation of oxygen on Jupiter's satellite Ganymede, and hence have more clues to its mode of production and stability, we have obtained spectral data from the Faint Object Spectrograph (FOS) for a single pole-to-pole latitudinal strip, along with several Wide Field Planetary Camera 2 (WFPC2)...
Binding of pyrene to aquatic and commercial humic substances: The role of molecular weight and aromaticity
Y.-P. Chin, G. R. Aiken, K.M. Danielsen
1997, Environmental Science & Technology (31) 1630-1635
The binding of pyrene to a number of humic substances isolated from various aquatic sources and a commercial humic acid was measured using the solubility enhancement method. The humic materials used in this study were characterized by various spectroscopic and liquid chromatography methods. A strong correlation was observed between the...
A note on the trilobite genus Dixiphopyge
D. K. Brezinski
1997, Annals of Carnegie Museum (66) 83-87
Recovery of the first nearly complete thoracopygon of the trilobite genus Dixiphopyge Brezinski from the Chouteau Formation of central Missouri aids in evaluating the paleoecology and taxonomic affinities of this genus. Dixiphopyge is an isopygous trilobite, suboval in outline, and possessing nine thoracic segments. At the apex of each axial...
Site amplifications for generic rock sites
D.M. Boore, W. B. Joyner
1997, Bulletin of the Seismological Society of America (87) 327-341
Seismic shear-wave velocity as a function of depth for generic rock sites has been estimated from borehole data and studies of crustal velocities, and these velocities have been used to compute frequency-dependent amplifications for zero attenuation for use in simulations of strong ground motion. We define a generic rock site...
Digital reproduction of historical aerial photographic prints for preserving a deteriorating archive
D.E. Luman, Christopher Stohr, L. Hunt
1997, Photogrammetric Engineering and Remote Sensing (63) 1171-1179
Aerial photography from the 1920s and 1930s is a unique record of historical information used by government agencies, surveyors, consulting scientists and engineers, lawyers, and individuals for diverse purposes. Unfortunately, the use of the historical aerial photographic prints has resulted in their becoming worn, lost, and faded. Few negatives exist...
The influence of habitat, prey abundance, sex, and breeding success on the ranging behavior of Prairie Falcons
J.M. Marzluff, Bryan A. Kimsey, Linda S. Schueck, Mary E. McFadzen, M.S. Vekasy, James C. Bednarz
1997, The Condor (99) 567-584
We studied the ranging behavior and habitat selection of radio-tagged Prairie Falcons (Falco mexicanus) during the breeding season in southwestern Idaho. The distribution and numbers of Townsend's ground squirrels (Spermophilus townsendii), the primary prey of Prairie Falcons in our study area, varied in response to drought during the study period....
Aftershocks: Are they earthquakes or afterthoughts?
S. E. Hough, L.M. Jones
1997, Eos, Transactions, American Geophysical Union (78) 505-508
We tend to view aftershocks as after-thoughts in their scientific as well as societal importance. The media often ask seismologists: “Was it just an aftershock?” with the “just” implying that aftershocks present little cause for concern. Seismologists themselves tend to dismiss the importance of events that...
Late-stage sinking of plutons
A. F. Glazner, D. M. Miller
1997, Geology (25) 1099-1102
Many granodiorite to diorite plutons in the Great Basin of western North America are surrounded by rim monoclines or anticlines that suggest relative downward movement of the plutons while wall rocks were hot and ductile. We propose that such plutons rise to a...
New allocyclic dimensions in a prograding carbonate bank: Evidence for eustatic, tectonic, and paleoceanographic control (late Neogene, Bahamas)
B. H. Lidz, D.F. McNeill
1997, Journal of Sedimentary Research B: Stratigraphy and Global Studies (68) 269-282
The deep-sea record, examined recently for the first time in a shallow-depocenter setting, has unveiled remarkable evidence for new sedimentary components and allocyclic complexity in a large, well-studied carbonate bank, the western Great Bahama Bank. The evidence is a composite foraminiferal signature - Paleocene to early Miocene (allogenic or reworked)...
Food and prey selection of recently released American shad (Alosa sapidissima) larvae
J. H. Johnson, D. S. Dropkin
1997, Journal of Freshwater Ecology (12) 355-358
We examined the diet composition and prey selection of 1,875 recently released American shad (Alosa sapidissima) larvae (approximately 18-d old). Larvae were collected in the Juniata River, Pennsylvania, during June in 1991 and 1992. Chironomid pupae were selected by shad larvae and were the major component in...
Effect of reaction time on the formation of disinfection byproducts
R. E. Rathbun
1997, Chemosphere (34) 2699-2713
The effect of reaction time on the trihalomethane and nonpurgeable total organic-halide formation potentials was determined by chlorinating water samples from the Mississippi, Missouri, and Ohio Rivers. Samples were collected for three seasons at 12 locations on the Mississippi from Minneapolis, Minnesota, to New Orleans, Louisiana, and on the Missouri...
Flow to a well of finite diameter in a homogeneous, anisotropic water table aquifer
Allen F. Moench
1997, Water Resources Research (33) 1397-1407
A Laplace transform solution is presented for the problem of flow to a partially penetrating well of finite diameter in a slightly compressible water table aquifer. The solution, which allows for evaluation of both pumped well and observation piezometer data, accounts for effects of well bore storage and skin and...
The 1936, 1945-1947, and 1950 earthquake sequences near Lassen Peak, California
R.D. Norris, K.L. Meagher, C.S. Weaver
1997, Journal of Geophysical Research B: Solid Earth (102) 449-457
Three vigorous earthquake sequences occurred near Lassen Peak in 1936, between 1945 and 1947, and in 1950; the latter two sequences included mainshocks of magnitude 5.0 and 5.5, respectively, and thousands of smaller events. No comparable earthquake sequences have occurred near Lassen Peak since 1950. The epicentral area lies within...
The California current of the last glacial maximum: reconstruction at 42°N based on multiple proxies
Joseph D. Ortiz, Alan C. Mix, Steven W. Hostetler, Michaele Kashgarian
1997, Paleoceanography (12) 191-205
Multiple paleoceanographic proxies in a zonal transect across the California Current near 42°N record modern and last glacial maximum (LGM) thermal and nutrient gradients. The offshore thermal gradient, derived from foraminiferal species assemblages and oxygen isotope data, was similar at the LGM to that at present (warmer offshore), but average...
Adsorption of SO2 onto oxidized and heat-treated activated carbon fibers (ACFs)
M. A. Daley, C.L. Mangun, J.A. DeBarr, S. Riha, A.A. Lizzio, G.L. Donnals, J. Economy
1997, Carbon (35) 411-417
A series of activated carbon fibers (ACFs) and heat-treated oxidized ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore surface chemistry and pore volume for the adsorption of SO2 and its catalytic conversion to H2SO4. For untreated ACFs, the initial rate...
Accretion of a New England (U.S.A.) salt marsh in response to inlet migration, storms, and sea-level rise
C. T. Roman, J.A. Peck, J.R. Allen, J.W. King, P.G. Appleby
1997, Estuarine, Coastal and Shelf Science (45) 717-727
Sediment accumulation rates were determined at several sites throughout Nauset Marsh (Massachusetts, U.S.A.), a back-barrier lagoonal system, using feldspar marker horizons to evaluate short-term rates (1 to 2 year scales) and radiometric techniques to estimate rates over longer time scales (137Cs,210Pb,14C). The barrier spit fronting theSpartina-dominated study site has a...
A three component model to estimate sensible heat flux over sparse shrubs in Nevada
A. Chehbouni, W. D. Nichols, E.G. Njoku, J. Qi, Y.H. Kerr, F. Cabot
1997, Remote Sensing Reviews (15) 99-112
It is now recognized that accurate partitioning of available energy into sensible and latent heat flux is crucial to understanding surface‐atmosphere interactions. This issue is more complicated in arid and semi‐arid regions where the relative contribution to surface fluxes from the soil and vegetation may vary significantly throughout the day...
Adsorption of SO2 on bituminous coal char and activated carbon fiber
Joseph A. DeBarr, Anthony A. Lizzio, Michael A. Daley
1997, Energy and Fuels (11) 267-271
The SO2 adsorption behaviors of activated carbons produced from Illinois coal and of commercially prepared activated carbon fibers (ACFs) were compared. There was no relation between surface area of coal-based carbons and SO2 adsorption, whereas adsorption of SO2 on the series of ACFs was inversely proportional to N2 BET surface...
The use of bulk collectors in monitoring wet deposition at high-altitude sites in winter
A.J. Ranalli, J.T. Turk, K. Campbell
1997, Water, Air, & Soil Pollution (95) 237-255
Concentrations of dissolved ions from samples collected by wet/dry collectors were compared to those collected by bulk collectors at Halfmoon Creek and Ned Wilson Lake in western Colorado to determine if bulk collectors can be used to monitor wet deposition chemistry in remote, high-altitude regions in winter. Hydrogen-ion concentration was...
Transport and degradation of semivolatile hydrocarbons in a petroleum-contaminated aquifer, Bemidji, Minnesota
E. T. Furlong, J. C. Koleis, G. R. Aiken
1997, ACS Symposium Series (671) 398-412
Polycyclic aromatic hydrocarbons (PAH) were used as probes to identify the processes controlling the transport and fate of aqueous semivolatile hydrocarbons (SVHCs) in a petroleum-contaminated aquifer near Bemidji, Minnesota. PAH and other SVHCs were isolated from ground water by field solid-phase extraction and analyzed using gas chromatography/mass spectrometry. Close to...
A self-modifying cellular automaton model of historical urbanization in the San Francisco Bay area
K.C. Clarke, S. Hoppen, L. Gaydos
1997, Environment and Planning B: Planning and Design (24) 247-261
In this paper we describe a cellular automaton (CA) simulation model developed to predict urban growth as part of a project for estimating the regional and broader impact of urbanization on the San Francisco Bay area's climate. The rules of the model are more complex than those of a typical...
