Origin of the Sudbury Complex by meteoritic impact: Neodymium isotopic evidence
B.E. Faggart Jr., A. R. Basu, Mitsunobu Tatsumoto
1985, Science (230) 436-439
Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 ± 21 × 106 years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium...
Contaminant residues in fish and sediments from lakes in the Atchafalaya River Basin (Louisiana)
Parley V. Winger, J. K. Andreasen
1985, Archives of Environmental Contamination and Toxicology (14) 579-586
Conversion of bottomland hardwood forests ℴ agricultural land has reduced habitat and water quality in many lakes in the floodplain of the lower Mississippi River. The objectives of this study were to ascertain current contaminant residue concentrations in fish and sediment from lakes in the Atchafalaya River Basin and to...
The relocation of microearthquakes in the northern Mississippi Embayment
M.C. Andrews, Walter D. Mooney, R.P. Meyer
1985, Journal of Geophysical Research Solid Earth (90) 10223-10236
Three-component seismograms, recorded by a small array of digital instruments in the northern Mississippi embayment, consistently show a high-amplitude phase on the vertical component that arrives approximately 0.8 s before the shear wave. On the basis of its timing and apparent velocity, this phase is identified as an S-P conversion from the...
The McKinley Sequence of granitic rocks: A key element in the accretionary history of southern Alaska
M. A. Lanphere, B.L. Reed
1985, Journal of Geophysical Research Solid Earth (90) 11413-11430
The McKinley sequence of granitic rocks consists of several discrete plutons in the central Alaska Range. Most of these plutons crop out south of the Denali fault system (DFS) in the Talkeetna quadrangle. Plutons of the McKinley sequence largely intrude deformed upper Meszoic flysch between the DFS and the northern...
Root zone of the late Proterozoic Salma caldera, northeastern Arabian Shield, Kingdom of Saudi Arabia
K.S. Kellogg
1985, Journal of Geophysical Research Solid Earth (90) 11253-11262
The eroded root of the late Proterozoic Salma caldera crops out in a striking, roughly elliptical feature, about 27 km long and 22 km wide, near the northeastern edge of the Arabian Shield. The caldera is genetically part of an elongate alkalic granitic massif (Jabal Salma) that extends 35 km...
Why deposits of longitudinal dunes are rarely recognized in the geologic record
David M. Rubin, Ralph E. Hunter
1985, Sedimentology (32) 147-157
Dunes that are morphologically of linear type, many of which are probably of longitudinal type in a morphodynamic sense, are common in modern deserts, but their deposits are rarely identified in aeolian sandstones. One reason for non-recognition of such dunes is that they can migrate laterally when they are not...
The 1983 hydraulic jump in Crystal Rapid: Implications for river- running and geomorphic evolution in the Grand Canyon
S. W. Kieffer
1985, Journal of Geology (93) 385-406
At Crystal Creek, a debris fan was emplaced in 1966, constricting the channel of the Colorado River to about 0.25 of its upstream width between 1967 and 1983, forming a major rapid. The hydraulics of Crystal Creek rapid are described, and an analysis is presented to support the hypothesis that...
1985 Rare Plant Study Findings. A Report to the California State Dept. of Fish and Game, Endangered Plant Species Program and the Superintendent, Channel Islands National Park
R. Fowler, W. L. Halvorson
1985, Report
No abstract available at this time...
Precambrian tholeiitic-dacitic rock-suites and Cambrian ultramafic rocks in the Pennine nappe system of the Alps: Evidence from Sm-Nd isotopes and rare earth elements
P. Stille, M. Tatsumoto
1985, Contributions to Mineralogy and Petrology (89) 184-192
Major element, trace element and Sm-Nd isotope analyses were made of polymetamorphic hornblendefelses, plagioclase amphibolites and banded amphibolites from the Berisal complex in the Simplon area (Italy, Switzerland) to determine their age, origin and genetic relationships. In light of major and rare earth element data, the hornblendefelses are inferred to...
HIGH-ANGLE AEOLIAN CROSSBEDDING AT TRAIL RIDGE, FLORIDA.
Eric Force, Tom Garnar
1985, Industrial Minerals
This paper described new evidence concerning the origin of the Trail Ridge mineral sands deposit in Florida. Rarely exposed sections of the orebody exhibit structures indicative of sand dune formation rather than coastal beach sand accumulation. The implications for mineral sands exploration, and therefore resources, in the southeastern USA are...
Ages of tuff beds at East African early hominid sites and sediments in the Gulf of Aden
A.M. Sarna-Wojcicki, C.E. Meyer, P.H. Roth, F. H. Brown
1985, Nature (313) 306-308
The early hominids of East Africa were dated by determining the ages of tuff beds at the sites. Despite much research using palaeomagnetic and K/Ar-dating techniques, some of those ages are still controversial 1,2. To obtain independent age estimates for these tephra layers, we have examined cores from DSDP Sites...
Analysis of low levels of rare earths by radiochemical neutron activation analysis
G.A. Wandless, J. W. Morgan
1985, Journal of Radioanalytical and Nuclear Chemistry Articles (92) 273-282
A procedure for the radiochemical neutron-activation analysis for the rare earth elements (REE) involves the separation of the REE as a group by rapid ion-exchange methods and determination of yields by reactivation or by energy dispersive X-ray fluorescence (EDXRF) spectrometry. The U. S. Geological Survey (USGS) standard rocks, BCR-1 and...
Mineralization of breccia pipes in northern Arizona
Karen J. Wenrich
1985, Economic Geology (80) 1722-1735
The Paleozoic sedimentary rocks on the Colorado Plateau of northern Arizona are host to hundreds ofbreccia pipes. The uranium and copper deposits in these breccia pipes transgress formation boundaries from the Mississippian Redwall Limestone to the Triassic Chinle Formation. They are not classic breccia pipes in that there is no...
Paraheritschioides, a new rugose coral genus from the Upper Pennsylvanian of Idaho
W.J. Sando
1985, Journal of Paleontology (59) 979-985
Colonial rugose corals are rare and generally poorly diversified in the Upper Pennsylvanian of the western interior region, conterminous USA. Paraheritschioides n.gen., which includes P. grandis n.sp., and P. complexa n.sp. from the Oquirrh Formation in Idaho, provides a new tool for distinguishing Upper Pennsylvanian rocks in the western interior....
Geochemistry and petrogenesis of lamproites, late cretaceous age, Woodson County, Kansas, U.S.A.
R.L. Cullers, S. Ramakrishnan, P. Berendsen, T. Griffin
1985, Geochimica et Cosmochimica Acta (49) 1383-1402
Lamproite sills and their associated sedimentary and contact metamorphic rocks from Woodson County, Kansas have been analyzed for major elements, selected trace elements, and strontium isotopic composition. These lamproites, like lamproites elsewhere, are alkalic (molecular K2O + Na2OAl2O3= 1.6–2.6">K2O + Na2OAl2O3= 1.6–2.6), are ultrapotassic <span...
Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska
R.E. Nelson, L. D. Carter
1985, Quaternary Research (24) 295-306
A 14-m-thick section of marine and nonmarine sediments of the Gubik Formation of northern Alaska, exposed in bluffs near Ocean Point on the Colville River, has been studied by means of pollen analysis. Pollen from the marine sediments, of probable late Pliocene age, records a boreal forest of spruce and...
Geology of the Silsilah ring complex, and associated tin mineralization, Kingdom of Saudi Arabia - a synopsis.
du Bray
1985, American Mineralogist (70) 1075-1086
A tin greisen deposit is associated with an alkali-feldspar granite that forms part of a ring complex at Jabal as Silsilah. The petrological and geochemical characteristics of the Fawwarah alkali-feldspar granite resemble those of granites located elsewhere that are also associated with deposits of Sn, W and rare metals. The...
The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California
B. R. Doe, M.H. Delevaux, J. P. Albers
1985, Economic Geology (80) 2136-2148
The tectonic setting comprising the West Shasta mining district has often been compared with that of primitive island arcs. Concentrations of uranium, thorium, and lead and lead isotope compositions were determined for Devonian ores and rocks of the West Shasta district, eastern Klamath Mountains, California, to help evaluate the tectonic...
Abundance fluctuations among benthic invertebrates in two pacific estuaries
Frederic H. Nichols
1985, Estuaries (8) 136-144
Long-term studies were used to examine (1) contrasting time scales and mechanisms of structural variations within two benthic communities and (2) the usefulness of long data sets for evaluating human impact. A 10-year study of a San Francisco Bay mudflat, the details of which are reported elsewhere, has revealed large...
Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration
D. Mulcahy, C.K. Jenes, R.J. Pascho
1984, Archives of Virology (80) 171-181
The incidence and amount of infectious hematopoietic necrosis (IHN) virus was determined in 10 organs and body fluids from each of 100 female sockeye salmon(Oncorhynchus nerka) before, during, and after their spawning migration into freshwater. Virus was found in high concentrations only in fish sampled during and after...
Recuperation of a severely debilitated wolf
L.D. Mech, U.S. Seal, S.M. Arthur
1984, Journal of Wildlife Diseases (20) 166-168
Opportunities are rare for determining the degree to which an animal can starve and still survive. Therefore we describe here an incident in which a wild wolf (Canis lupus) starved almost to death and was then restored to her former free-ranging state. The incident took place in northern Lake County,...
Geochemical investigation of Archaean Bimodal and Dwalile metamorphic suites, Ancient Gneiss Complex, Swaziland
D.R. Hunter, F. Barker, Hugh T. Millard Jr.
1984, Precambrian Research (24) 131-155
The bimodal suite (BMS) comprises leucotonalitic and trondhjemitic gneisses interlayered with amphibolites. Based on geochemical parameters three main groups of siliceous gneiss are recognized: (i) SiO2 < 73%, Al2O3 > 14%, and fractionated light rare-earth element (REE) and flat heavy REE patterns; (ii) SiO2 and Al2O3 contents similar to (i) but with strongly fractionated...
Interlaboratory comparison of mineral constituents in a sample from the Herrin (No. 6) coal bed from Illinois
Robert B. Finkelman, F.L. Fiene, R.N. Miller, F.O. Simon
1984, Circular 932
Approximately 20 kg of the Herrin (No. 6) coal was collected from a strip mine in St. Clair County, Ill. A 10-kg portion was ground to -60 mesh, homogenized, and riffled into 128 splits of 70-80 g each. Homogeneity of these splits was confirmed by moisture, ash, and sulfur analyses...
Maps showing mines, quarries, prospects, and exposures in the Devils Fork Roadless Area, Scott County, Virginia
Paul T. Behum
1984, Miscellaneous Field Studies Map 1611-D
The Wilderness Act (Public Law 88-577, September 3, 1964) and related acts require the U.S. Geological Survey and the U.S. Bureau of Mines to survey certain areas on Federal lands to determine their mineral resource potential. Results must be made available to the public and be submitted to the President and...
Reconnaissance geology of the Qufar Quadrangle, sheet 27/41 D, Kingdom of Saudi Arabia
K.S. Kellogg
1984, Open-File Report 84-159
The Qufar quadrangle, south of the city of Ha' il in the northern Arabian Shield is underlain by late Proterozoic granitic and dioritic rocks and two volcano-sedimentary sequences. Phanerozoic rocks include a few outcrops of the Cambrian and Ordovician Saq Sandstone and small remnants of Miocene basalt flows and plugs. The...
