Fluid-inclusion evidence on the environment of formation of mineral deposits of the southern Appalachian valley
Edwin Roedder
1971, Economic Geology (66) 777-791
Approximately 1,330 fluid inclusions were studied in samples of ore and gangue minerals from both massive ore and late-stage vugs from a series of Appalachian deposits and five active mines in the East Tennessee zinc districts. Most primary inclusions in sphalerite, fluorite, dolomite, and quartz...
Ore fluids in the porphyry copper deposit at Copper Canyon, Nevada
J. Thomas Nash, Ted G. Theodore
1971, Economic Geology (66) 385-399
The large, low-grade copper and gold deposit at Copper Canyon, Lander County, Nevada, formed in the contact metasomatic environment adjacent to a shallow Tertiary intrusion. Vein and disseminated chalcopyrite-pyrite-pyrrhotite-arsenopyrite mineralization, with lesser amounts of gold, galena, sphalerite, marcasite, and siderite occur in the Upper Cambrian...
Radiometric age (Late Ordovician) of the Quincy, Cape Ann, and Peabody Granites from eastern Massachusetts
Robert E. Zartman, Richard F. Marvin
1971, Bulletin of the Geological Society of America (82) 937-957
A geochronologic study of several intrusive bodies of alkalic granite from eastern Massachusetts yields the following radiometric ages (in millions of years).Rock unitAmphibole K-ArWhole-rock Rb-Sr isochron ...
Petrologic and geophysical nature of serpentinites
Robert G. Coleman
1971, Bulletin of the Geological Society of America (82) 897-917
Mineralogically, serpentinites consist predominantly of lizardite, clinochrysotile, and antigorite. Recent work has shown that these minerals are not polymorphs. Chrysotile is the only mineral recognized as a synthetic product in experimental studies of the system MgO-SiO2-H2O. Antigorite seems to be stable at higher temperatures than lizardite or chrysotile. The density...
Basin and range structure: A system of horsts and grabens produced by deep-seated extension
John H. Stewart
1971, Bulletin of the Geological Society of America (82) 1019-1043
Basin and Range structure can be interpreted as a system of horsts and grabens produced by the fragmentation of a crustal slab above a plastically extending substratum. According to this view, the extension...
A shortcut for computing stream depletion by wells using analog or digital models
O. James Taylor
1971, Groundwater (9) 9-11
Theory indicates that the effect of a discharging well on a nearby stream is independent of the length of the reach. The theory was confirmed using a digital computer model of short and long reaches of a stream-aquifer system. Digital computations using short reaches of most...
Data file, Continental Margin Program, Atlantic Coast of the United States: vol. 2 sample collection and analytical data
John C. Hathaway
1971, Report
The purpose of the data file presented below is twofold: the first purpose is to make available in printed form the basic data relating to the samples collected as part of the joint U.S. Geological Survey - Woods Hole Oceanographic Institution program of study of the Atlantic continental margin...
A paleohydrologic model for mineralization of the White Pine copper deposit, northern Michigan
Walter S. White
1971, Economic Geology (66) 1-13
Pertinent physical properties of the upper Keweenawan rocks can be measured or inferred within a sufficiently narrow range to make the quantitative evaluation of various paleohydrologic models for the origin of the White Pine copper deposit feasible. The approach is illustrated here by calculations for...
Coronadite — Modes of occurrence and origin
D. F. Hewett
1971, Economic Geology (66) 164-177
The lead manganate, "coronadite," was first recognized at the Coronado mine in the Morenci district, Arizona, by Lindgren in 1903. Several years later, the identity of the mineral was questioned and it was not until 1932 that Orcel recognized it in material from Morocco. Since...
An evaluation of procedures used in computing chemical denudation rates
Richard J. Janda
1971, Bulletin of the Geological Society of America (82) 67-79
Computations of chemical denudation rates (that is, the average rate of lowering of the earth's crust by chemical processes) should be based only upon those components of dissolved loads of streams that are derived from chemical weathering of rocks and soils, even though identification of those components is difficult and...
Thin skin distension in Tertiary rocks of southeastern Nevada
R. Ernest Anderson
1971, Bulletin of the Geological Society of America (82) 43-58
Volcanic rocks of late Tertiary age, aggregating about 17,000 ft, accumulated on a surface of low relief cut on Precambrian rocks in the Basin and Range province south of Lake Mead, in Nevada and Arizona. They consist mostly of lava and flow breccia of intermediate composition with minor ash-flow tuff,...
A comment concerning the applicability of the “open system” model to dating of fossil bones from San Joaquin soil, California
Barney J. Szabo
1971, Earth and Planetary Science Letters (10) 252-252
No abstract available....
Trees and streams: The efficiency of branching patterns
Luna Bergere Leopold
1971, Journal of Theoretical Biology (31) 339-354
Extending the analysis of branching patterns of the drainage net of rivers, originated by Horton, the relation of average numbers and lengths of tree branches to size of branch was investigated. Size of branch was defined by branch order, or its position in the hierarchy of tributaries. It was found...
Aeromagnetic study of the midcontinent gravity high of central United States
Elizabeth R. King, Isidore Zietz
1971, Geological Society of America Bulletin (82) 2187-2208
A composite map of detailed aeromagnetic surveys over the midcontinent gravity high provides coverage of the 600-mi-long buried belt of mafic rocks of the Keweenawan Series from their outcrop localities in Minnesota and Wisconsin through Iowa and Nebraska. A map of the subsurface extent of the mafic rocks, based on...
A Pliocene flora and insect fauna from the Bering Strait region
D.M. Hopkins, J.V. Matthews, J. A. Wolfe, M.L. Silberman
1971, Palaeogeography, Palaeoclimatology, Palaeoecology (9) 211-231
A flood-plain forest has been preserved beneath a lava flow that invaded the Inmachuk River Valley in the northern part of the Seward Peninsula, Alaska, during the Pliocene Epoch. The fossil flora is of great biogeographic interest because of its position (Fig. 1)...
Paleomagnetism of San Cristobal Island, Galapagos
A. Cox
1971, Earth and Planetary Science Letters (11) 152-160
Isla San Cristobal, the most easterly of the Galapagos Islands, consists of two parts: a large volcano constitutes the southwest half of the island and an irregular apron of small cones and flows makes up the northeast half. As some of the...
Kaersutite - A product of reaction between pargasite and basanite at Dish Hill, California
H. G. Wilshire, L. C. Calk, E.C. Schwarzman
1971, Earth and Planetary Science Letters (10) 281-284
Paragasitic amphibole, occurring interstitially and as veins in peridotite inclusions in basanite, has reacted with the host basanite to form kaersutitic amphibole. The amphibole compositions vary with respect to distance from the edge of the xenolith; iron, titanium, and potassium contents are...
Fluid inclusions in quartz crystals from South-West Africa
K.A. Kvenvolden, E. Roedder
1971, Geochimica et Cosmochimica Acta (35) 1209-1229
Quartz crystals from calcite veins of unknown age in Precambrian metasedimentary rocks at Geiaus No. 6 and Aukam farms in South-West Africa contain both primary and secondary inclusions filled with one or a variable combination of: organic liquid, moderately saline aqueous liquid, dark-colored...
Visceral granuloma in brook trout (Salvelinus fontinalis)
C. E. Dunbar, R. L. Herman
1971, Journal of Nutrition (101) 1445-1452
Brook trout were fed a synthetic diet with suspect diet components added or a meat-meal diet with individual components removed to determine their effect on the incidence of visceral granuloma. Removal or addition of cottonseed meal had the greatest effect on incidence. Gossypol was not the causative agent. The disease...
Limited-interval definitions of the photometric functions of lunar crater walls by photography from orbiting Apollo
R.L. Wildey
1971, Icarus (15) 93-99
By the use of only relative photometry (intraframe) it is shown that the photometric functions of material reposed on the inner walls of some of the ypunger lunar craters photographed on the far side of the Moon from the Apollo 11 Command Module...
Genetic implications of the shapes of martian and lunar craters
R.J. Pike
1971, Icarus (15) 384-395
Craters on Mars and the Moon are alike in that larger craters differ in shape from smaller ones, and older craters differ in shape from younger ones. Smoothed depth-diameter curves for 41 large martian craters photographed by Mariner IV inflect at a crater...
Imaging of Mercury and Venus from a flyby
B. C. Murray, M. J. S. Belton, G. Edward Danielson, M. E. Davies, G. P. Kuiper, B. T. O’Leary, V.E. Suomi, N.J. Trask
1971, Icarus (15) 153-173
This paper describes the results of study of an imaging experiment planned for the 1973 Mariner Venus/Mercury flyby mission. Scientific objectives, mission constraints, analysis of alternative systems, and the rationale for final choice are presented. Severe financial constraints ruled out the best technical alternative for flyby imaging, a film/readout system,...
Uranium-series dating of some pleistocene marine deposits in Southern California
Barney J. Szabo, J. G. Vedder
1971, Earth and Planetary Science Letters (11) 283-290
Analyses of uranium isotopes and their long-lived daughter products showed evidence of uranium migration in most of the 22 fossil mollusk shell samples from marine terrace deposits in southern California. Two samples, however, remained an ideal closed system as indicated by concordant230Th/234U...
Effects of temperature on electrolyte balance and osmoregulation of the alewife (Alosa pseudoharengus) in fresh and sea water
Jon G. Stanley, Peter J. Colby
1971, Transactions of the American Fisheries Society (100) 624-638
A study of the effects of temperature and salinity on ionoregulation in the alewife, Alosa pseudoharengus, revealed that concentrations of sodium, potassium, and calcium in plasma and muscle were similar in fish adapted to fresh water and those adapted to sea water. The non-stressed alewife is apparently an excellent...
Population biology of lake trout (Salvelinus namaycush) of Lake Superior before 1950
Gary T. Sakagawa, Richard L. Pycha
1971, Journal of the Fisheries Research Board of Canada (28) 65-71
Scale samples collected in 1948 were used to estimate the instantaneous total mortality rate (0.70) and growth for lake trout (Salvelinus namaycush) in Lake Superior before the population had been significantly reduced by the sea lamprey (Petromyzon marinus). Indirect evidence indicates that the instantaneous natural mortality rate was probably 0.10–0.25....
