EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.
Victor G. Mossotti, James R. Lindsay, Michael F. Hochella Jr.
1987, Materials Performance (26) 47-52
Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were...
Turbidity as a control on phytoplankton biomass and productivity in estuaries
J. E. Cloern
1987, Continental Shelf Research (7) 1367-1381
In many coastal plain estuaries light attenuation by suspended sediments confines the photic zone to a small fraction of the water column, such that light limitation is a major control on phytoplankon production and turnover rate. For a variety of estuarine systems (e.g. San Francisco Bay, Puget Sound, Delaware Bay,...
Heat capacity and thermodynamic properties of andradite garnet, Ca3Fe2Si3O12, between 10 and 1000 K and revised values for ΔfGom (298.15 K) of hedenbergite and wollastonite
Richard A. Robie, Zhao Bin, Bruce S. Hemingway, Mark D. Barton
1987, Geochimica et Cosmochimica Acta (51) 2219-2224
The heat capacity of synthetic andradite garnet (Ca3Fe2Si3O12) was measured between 9.6 and 365.5 K by cryogenic adiabatic calorimetry and from 340 to 990 K by differential scanning calorimetry. At 298.15 KCop,m and Som are 351.9 ± 0.7 and 316.4 ± 2.0 J/(mol·K), respectively. Andradite has a λ-peak in Cop,m with a maximum at...
Evaluation of the stability of gas hydrates in Northern Alaska
A. Kamath, S. P. Godbole, R. D. Ostermann, T. S. Collett
1987, Cold Regions Science and Technology (14) 107-119
The factors which control the distribution of in situ gas hydrate deposits in colder regions such as Northern Alaska include; mean annual surface temperatures (MAST), geothermal gradients above and below the base of permafrost, subsurface pressures, gas composition, pore-fluid salinity and the soil condition. Currently existing data on the above...
Effects of weathering on biological marker and aromatic hydrocarbon composition of organic matter in Phosphoria shale outcrop
J.L. Clayton, J. D. King
1987, Geochimica et Cosmochimica Acta (51) 2153-2157
GC-MS analyses were performed on core samples collected from a shale outcrop of the Permian Phosphoria Formation in Utah, U.S.A., to study effects of weathering on selected biological marker and aromatic (phenanthrene) hydrocarbon compounds. Among the biological markers, the most important weathering effects are a decrease in the <span id="MathJax-Element-1-Frame"...
On regional geomagnetic charts
L.R. Alldredge
1987, Journal of Geomagnetism & Geoelectricity (39) 723-738
When regional geomagnetic charts for areas roughly the size of the United States were compiled by hand, some large local anomalies were displayed in the isomagnetic lines. Since the late nineteen sixties, when the compilation of charts using computers and mathematical models was started, most of the details...
Evolution and petroleum geology of Amlia and Amukta intra-arc summit basins, Aleutian Ridge
E.L. Geist, J.R. Childs, D.W. Scholl
1987, Marine and Petroleum Geology (4) 334-352
Amlia and Amukta Basins are the largest of many intra-arc basins formed in late Cenozoic time along the crest of the Aleutian Arc. Both basins are grabens filled with 2-5 km of arc-derived sediment. A complex system of normal faults deformed the basinal strata. Although initial deposits of late Micocene...
Geothermometry of Kilauea Iki lava lake, Hawaii
Rosalind Tuthill Helz, C.R. Thornber
1987, Bulletin of Volcanology (49) 651-668
Data on the variation of temperature with time and in space are essential to a complete understanding of the crystallization history of basaltic magma in Kilauea Iki lava lake. Methods used to determine temperatures in the lake have included direct, downhole thermocouple measurements and Fe-Ti oxide geothermometry. In addition, the...
Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State
R. A. Zielinski, R.R. Schumann
1987, Journal of Geochemical Exploration (27) 281-298
Douglas fir trees and associated soils were sampled from the slopes of a small (∼4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger...
Moment tensor solutions estimated using optimal filter theory for 51 selected earthquakes, 1980-1984
S.A. Sipkin
1987, Physics of the Earth and Planetary Interiors (47) 67-79
The 51 global events that occurred from January 1980 to March 1984, which were chosen by the convenors of the Symposium on Seismological Theory and Practice, have been analyzed using a moment tensor inversion algorithm (Sipkin). Many of the events were routinely analyzed as part of the National Earthquake Information...
Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations
R.M. Iverson, J. J. Major
1987, Geological Society of America Bulletin (99) 579-594
Simple ground-water flow analyses can clarify complex empirical relations between rainfall and landslide motion. Here we present detailed data on rainfall, ground-water flow, and repetitive seasonal motion that occurred from 1982 to 1985 at Minor Creek landslide in northwestern California, and we interpret these data in the context of physically...
Plate-tectonic evolution of the western U.S.A.
W. Hamilton
1987, Episodes (10) 271-276
Changing interactions of lithospheric plates provide the framework for this review of the 3100 m.y. geological history of some 3 million km2 of mountains, deserts, plateaux and plains. The Precambrian to Neogene development of the western U.S.A. is outlined in terms of plate collisions, subduction events and deformation of lithospheric...
On the interpretation of the geomagnetic energy spectrum
E.R. Benton, L.R. Alldredge
1987, Physics of the Earth and Planetary Interiors (48) 265-278
Two recent high-degree magnetic energy spectra, based mostly on MAGSAT data, are compared and found to agree very well out to order and degree n = 15, but the spectrum remains somewhat uncertain for higher degrees. The hypothesis that a primary break in the slope of the spectrum, plotted semi-logarithmically,...
Generation of liquid water on Mars through the melting of a dusty snowpack
G.D. Clow
1987, Icarus (72) 95-127
The possibility that snowmelt could have provided liquid water for valley network formation early in the history of Mars is investigated using an optical-thermal model developed for dusty snowpacks at temperate latitudes. The heating of the postulated snow is assumed to...
A model of geomagnetic secular variation for 1980-1983
N.W. Peddie, A.K. Zunde
1987, Physics of the Earth and Planetary Interiors (48) 324-329
We developed an updated model of the secular variation of the main geomagnetic field during 1980 through 1983 based on annual mean values for that interval from 148 worldwide magnetic observatories. The model consists of a series of 80 spherical harmonics, up to and including those of degree and order...
Volatilization, transport and sublimation of metallic and non-metallic elements in high temperature gases at Merapi Volcano, Indonesia
R.B. Symonds, William I. Rose Jr., M.H. Reed, F.E. Lichte, David L. Finnegan
1987, Geochimica et Cosmochimica Acta (51) 2083-2101
Condensates, silica tube sublimates and incrustations were sampled from 500–800°C fumaroles and lava samples were collected at Merapi Volcano, Indonesia in Jan.–Feb., 1984. With respect to the magma, Merapi gases are enriched by factors greater than 105 in Se, Re, Bi and Cd; 104–105 in Au, Br, In, Pb and W; 103–104 in...
Ice erosion of a sea-floor knickpoint at the inner edge of the stamukhi zone, Beaufort Sea, Alaska
P. W. Barnes, J.L. Asbury, D.M. Rearic, C.R. Ross
1987, Marine Geology (76) 207-222
In 1981 and 1982, detailed bathymetric and side-scan sonar surveys were made of an area of the sea floor north of Prudhoe Bay, Alaska, to study the changing characteristics of the seabed at the inner boundary of the stamukhi zone, the...
Solid-state 13C NMR studies of dissolved organic matter in pore waters from different depositional environments
William H. Orem, Patrick G. Hatcher
1987, Organic Geochemistry (11) 73-82
Dissolved organic matter (DOM) in pore waters from sediments of a number of different depositional environments was isolated by ultrafiltration using membranes with a nominal molecular weight cutoff of 500. This > 500 molecular weight DOM represents 70–98% of the total DOM in these pore waters. We determined the gross...
Fabric and its relation to sedimentologic and physical properties of near-surface sediment, Shelikof Strait and Alsek prodelta, Alaska
M.E. Torresan, W. C. Schwab
1987, Journal of Sedimentary Petrology (57) 408-418
To investigate the possible relation between the fabric (microstructural arrangement of particles) of a fine-grained sedimentary deposit and the depositional and environmental processes of that deposit, the fabric of sediment samples from the sea floor of two different depositional settings, Shelikof Strait and...
Characteristics of hydrolysis of the complex Na2SnF6 in hydrothermal solutions-An experimental study
Y. Wang, C. I-Ming
1987, Chinese Journal of Geochemistry (6) 372-382
Characteristics of hydrolysis of the complex Na2SnF6, which is used as the starting material, in hydrothermal solutions have been studied at 200-602??C and 1 kbar. Experimental results show that intense hydrolysis of Na2SnF6 occurs at high temperatures and that with the rise of temperature the hydrolysis will become more intense....
New perspectives on the eruption of 1912 in the valley of ten thousand smokes, Katmai National Park, Alaska
W. Hildreth
1987, Bulletin of Volcanology (49) 680-693
New data extend our understanding of the 1912 eruption, its backfilled vent complex at Novarupta, and magma-storage systems beneath adjacent stratovolcanoes. Initial Plinian rhyolite fallout is confined to a narrow downwind sector, and its maximum thickness may occur as far as 13 km from source. In contrast, the partly contemporaneous...
The Upper Paleozoic pebbly mudstone facies of peninsular Thailand and western Malaysia - Continental margin deposits of Palaeoeurasia - Discussion
P.H. Stauffer, L.C. Peng
1987, Geologische Rundschau (76) 945-948
[No abstract available]...
Geological hazards: programs and research in the USA
J.R. Filson
1987, Episodes (10) 292-295
Geological hazards have been studied for centuries, but government support of research to lessen their effects is relatively new. This article briefly describes government programs and research under way in the U.S.A. that are directed towards reducing losses of life and property from earthquakes, volcanic eruptions and landslides. -Author...
New U/Pb Ages from Granite and Granite Gneiss in the Ruby Geanticline and Southern Brooks Range, Alaska
W. W. Patton Jr., T. W. Stern, Joseph G. Arth, C. Carlson
1987, Journal of Geology (95) 118-126
New U/Pb zircon ages from the Ray Mountains of central Alaska clarify the plutonic history of the Ruby geanticline and support earlier suggestions that the Ruby geanticline and S Brooks Range were once parts of the same tectonostratigraphic terrane. U/Pb zircon ages of 109 to 112 Ma from the Ray...
Basement thrust sheets in the Clearwater orogenic zone, central Idaho and western Montana
B. Skipp
1987, Geology (15) 220-224
The Clearwater orogenic zone in central Idaho and western Montana contains at least two major northeast-directed Cordilleran thrust plates of Early Proterozoic metasedimentary and metaigneous rocks that overrode previously folded Middle Proterozoic rocks of the Belt basin in Cretaceous time. The northeastward migration...
