R. F. Wendlandt, J.S. Huebner, W.J. Harrison
1982, American Mineralogist (67) 170-174
-K.A.R....
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Publication Extents
Not all publications have extents, not all extents are completely accurateG. L. Kennedy, K. R. Lajoie, J.F. Wehmiller
1982, Nature (299) 545-547
Recent studies using the extent of racemization of amino acids to date fossil mollusc shells in the Arctic1, the British Isles2 and on the Atlantic3,4 and Pacific5-13 coasts of North America have relied mainly on theoretical kinetic models of racemization. Ages generated in this fashion are highly model dependent and...
Wendell A. Duffield, Laurent Stieltjes, Jacques Varet
1982, Journal of Volcanology and Geothermal Research (12) 147-160
Piton de la Fournaise, on the island of La Réunion, and Kilauea volcano, on the island of Hawaii, are active, basaltic shield volcanoes growing on the flanks of much larger shield volcanoes in intraplate tectonic environments. Past studies have shown that the average rate of magma production and the chemistry...
E. Callender
1982, Hydrobiologia (91-92) 431-446
The flux of dissolved reactive phosphate from Potomac riverine and estuarine sediments is controlled by processes occurring at the water-sediment interface and within surficial sediment. In situ benthic fluxes (0.1 to 2.0 mmoles m-2 day-1) are generally five to ten times higher than calculated diffusive fluxes (0.020 to 0.30 mmoles...
A.C. Sigleo, T.C. Hoering, G.R. Helz
1982, Geochimica et Cosmochimica Acta (46) 1619-1626
Colloidal material in the size range 1.2 nm to 0.4 μm was isolated by ultrafiltration from Chesapeake Bay and Patuxent River waters (U.S.A.). Temperature controlled, stepwise pyrolysis of the freeze-dried material, followed by gas chromatographic-mass spectrometric analyses of the volatile products indicates that the primary organic components of this polymer...
Yinzhu Zhou, Y.-L. Ren, B.F. Bohor
1982, International Journal of Coal Geology (2) 49-77
We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and...
L.W. Dennis, G.E. Maciel, Patrick G. Hatcher, Bernd R. T. Simoneit
1982, Geochimica et Cosmochimica Acta (46) 901-907
Cretaceous black shales from DSDP Leg 41, Site 368 in the Eastern Atlantic Ocean were thermally altered during the Miocene by an intrusive basalt. The sediments overlying and underlying the intrusive body were subjected to high temperatures (up to ~ 500°C) and, as a result, their kerogen was significantly altered....
Niel Plummer, Eric T. Sundquist
1982, Geochimica et Cosmochimica Acta (46) 247-258
We have calculated the total individual ion activity coefficients of carbonate and calcium, and , in seawater. Using the ratios of stoichiometric and thermodynamic constants of carbonic acid...
Robert H. Webb, Evelyn B. Newman
1982, Environmental Conservation (9) 245-248
No abstract available....
R. E. Hunter, H. Clifton
1982, Journal of Sedimentary Petrology (52) 127-143
Cyclic deposits containing hummocky cross-stratification occur in the upper part of the Cape Sebastian Sandstone of Bourgeois (1980), a shallow marine transgressive sandstone of Late Cetaceous age on the southern Oregon coast. The cycles average 1.6 m in thickness and consist, where complete,...
Dennis D. Eberl, Blair F. Jones, Hani N. Khoury
1982, Clays and Clay Minerals (30) 321-326
Mixed-layer clays composed of randomly interstratified kerolite/stevensite occur as lake and/or spring deposits of probable Pliocene and Pleistocene age in the Amargosa Desert of southern Nevada, U.S.A. The percentage of expandable layers of these clays, determined from computer-simulated X-ray diffractograms, ranges from almost 0 to about 80%. This range in...
C. W. Naeser, P. Toghill, R. J. Ross Jr.
1982, Geological Magazine (119) 213-214
Four samples of Longmyndian and Uriconian strata from S of Shrewsbury, England have been processed for apatite and/or zircon fission-track ages. The resultant ages illustrate how depth of burial may affect fission-track ages. The analytical procedures followed were as described in Naeser (1979).-from Authors...
A.R. Chivas, A.S. Andrew, A.K. Sinha, J. R. O’Neil
1982, Nature (300) 139-143
The Koloula Igneous Complex, on the island of Guadalcanal, consists of a low-K calc-alkaline sequence of 26 different intrusive phases. The major intrusions are characterized by K/Rb>400, Rb/Sr<0.06, ?? 18O of 5.7 to 7.2 and uniform 87Sr/86Sr of 0.70372. This article presents the first data describing oxygen and strontium isotopic...
R.F. Sanford
1982, Geology (10) 348-352
Qualitative and numerical simulation of regional groundwater flow in the Colorado Plateau during Late Jurassic and Early Cretaceous time has led to a model of U deposition in areas of upwelling solutions. Palaeographic reconstruction shows that surface drainage and groundwater flow was generally to the NE and E. Groundwater flowing...
B. McGregor, W.L. Stubblefield, William B. F. Ryan, D.C. Twichell
1982, Geology (10) 27-30
Midrange sidescan sonar data (swath width = 5 km) show that a system of gullies and small channels feeds into large submarine canyons on the Middle Atlantic Continental Slope of the United States. The surveyed canyons all have relatively flat floors, but they...
F. E. Senftle, A. N. Thorpe, C.C. Alexander, R. B. Finkelman
1982, Fuel (61) 81-86
Although no significant major-element contamination is introduced by grinding coal in a steel pulverizer, abraded steel particles can conceivably affect the magnetic properties of pulverized coal. Magnetic and scanning-electron-microscope analyses of pulverized coal and coal fragments from the Herrin No. 6 seam in Illinois showed ferromagnetic and superparamagnetic contamination from...
T. D. Hamilton, Curtis M. Obi
1982, Arctic and Alpine Research (14) 13-20
Some 70 pingos occur at 27 separate localities within and near the Brooks Range. The pingos are distributed through mountain valleys at altitudes up to 725 m and in terrain glaciated as recently as late Wisconsinan time. Most are open-system forms; possible closed-system pingos are present at only a single...
C.R. Thornber, J.S. Huebner
1982, American Mineralogist (67) 1144-1154
Some iron crucibles contain impurities of Mn, Ti and other elements. Such impurities may alter the fO2 of the system and induce crucible-charge interactions. Pretreatment of impure iron crucibles in a CO2-CO atmosphere at 1050oC, under conditions slightly more reducing than Fe-Fe1-xO, minimizes undesirable changes in the bulk composition of...
N. D. Naeser, J.A. Westgate, O.L. Hughes, T. L. Pewe
1982, Canadian Journal of Earth Sciences (19) 2167-2178
Six distal tephra beds from the Yukon Territory and Alaska have been dated by the fission-track method. Zircon and glass ages were determined for the Fort Selkirk and Lost Chicken tephra beds, but only glass ages for the others.Assuming that no track fading has occurred in the glass, Old Crow...
Charles Milton, Howard T. Evans Jr., Robert G. Johnson
1982, Mineralogical Magazine (46) 351-355
Dwornikite, (Ni1−xFex)SO4 · H2O is a member of the kieserite group, monoclinic with space group C2/c. Specimens from Minasragra, Peru with x ∼ 0.1 have a unit cell with a = 6.839(2), b = 7.582(2), c = 7.474(2) Å, and β = 117.85(2)°. The six strongest lines of the...
I. Barnes, T. S. Presser, M. Saines, P. Dickson, A. F. K. Van Groos
1982, Chemical Geology (35) 147-154
Highly-alkaline (pH > 12.5) meteoric waters of a Ca2+OH−-type issue from naturally calcined bituminous marl. The cold (16.5 ≤ T(°C) ≤ 19.1) waters are super-saturated with minerals thought to be of high-temperature origin....
D.A. Clague, F.A. Frey
1982, Journal of Petrology (23) 447-504
The Honolulu Volcanics comprises small volume, late-stage (post-erosional) vents along rifts cutting the older massive Koolau tholeütic shield on Oahu, Hawaii. Most of these lavas and tuff of the Honolulu Volcanics have geochemical features expected of near-primary magmas derived from a peridotite source containing Fo87–89 olivine; e. g. 100 Mg/(Mg...
R. G. Martin, A.H. Bouma
1982, Marine Geotechnology (5) 63-91
Large diapiric and nondiapiric masses of Jurassic salt and Tertiary shale underlie the northern Gulf of Mexico continental slope and adjacent outer continental shelf. Local steepening of the sea floor in response to the vertical growth of these structures is a serious concern to those involved in the site selection...
R.H. Meade
1982, Journal of Geology (90) 235-252
The history of sediment and its movement in the Atlantic drainage demonstrate some of the difficulties of modeling sediment on a river-basin scale. Soil erosion was accelerated by a factor of at least 10 when European settlers cleared forests and planted crops. Although increasing soil-conservation practice and decreasing crop farming...
Pat S. Chavez Jr., Brian P. Bauer
1982, Remote Sensing of Environment (12) 23-38
Edge enhancement is a technique that can be considered, to a first order, a correction for the modulation transfer function of an imaging system. Digital imaging systems sample a continuous function at discrete intervals so that high-frequency information cannot be recorded at the same precision as lower frequency data. Because...