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Page 6378, results 159426 - 159450

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Publication Extents

Not all publications have extents, not all extents are completely accurate
A decade of international cooperation brings a standard seismic point of view
H. S Whitcomb Jr.
1971, Earthquake Information Bulletin (USGS) (3) 16-19
Whether in a castle in Italy, a police station in Iceland, o an abandoned gold mine in Australia, the sensitive instruments in the Worldwide Seismograph Network send a steady flow of standard earthquake records to the geophysical scientific community. They provide the raw data that make possible very precise earthquake...
Blood cell lineage in the sea lamprey, Petromyzon marinus (Pisces: Petromyzontidae)
George W. Piavis, James L. Hiatt
1971, Copeia (1971) 722-728
Blood cell types of the sea lamprey, Petromyzon marinus, are described and identified and the lineage of mature circulating cells in peripheral blood is traced to blast cells in the hematopoietic fat body. The fat body appears to be the phylogenetic precursor of bone marrow in higher forms, since blood...
Alewife dieoffs: Why do they occur?
Peter J. Colby
1971, Limnos (4) 18-27
Periodid midwinter, early spring, and summer mortalities of alewives (Alosa pseudoharengus) have been common in the Great Lakes since the first appearance of the silvery marine invader in Lake Ontario in the mid-1870's. In 1967 a nationally publicized dieoff of tremendous magnitude (estimated at several hundred million pounds of...
Seasonal distribution of zooplankton in the northern basin of Lake Chad
A.H. Robinson, Patricia K. Robinson
1971, Journal of Zoology (163) 25-61
More than 300 pairs of fine and coarse mesh plankton net samples were collected in the northern basin of Lake Chad during an 18-month period, June 1967 to November 1968. The seasonal distribution and abundance of the dominant species of Rotifera and Crustacea are given in addition to a general...
Selective food preferences of walleyes of the 1959 year class in Lake Erie
John W. Parsons
1971, Transactions of the American Fisheries Society (100) 474-485
Stomachs were examined from 1,473 walleyes (Stizostedion vitreum vitreum) of the 1959 year class collected in western Lake Erie from June 1959 to October 1960. In the same period, the relative abundance and lengths of potential forage species were determined from trawl catches. The walleye fed almost entirely on fish....
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...
Reactivity of clay minerals with acids and alkalies
Dorothy Carroll, Harry C. Starkey
1971, Clays and Clay Minerals (19) 321-333
One-g samples of a montmorillonite, a metabentonite, an illite, two kaolinites, and three halloysites were treated with 50 ml of hydrochloric acid (6⋅45 N, 1:1), acetic acid (4⋅5 N, 1:3), sodium hydroxide (2⋅8 N), sodium chloride solution (pH 6⋅10; Na = 35‰; Cl = 21⋅5‰), and natural sea water (pH...
Mixed-layer kaolinite-montmorillonite from the Yucatan Peninsula, Mexico
L.G. Schultz, A.O. Shepard, P.D. Blackmon, H.C. Starkey
1971, Clays and Clay Minerals (19) 137-150
Clay beds 1–2 m thick and interbedded with marine limestones probably of early Eocene age are composed of nearly pure mixed-layer kaolinite-montmorillonite. Particle size studies, electron micrographs, X-ray diffraction studies, chemical analyses, cation exchange experiments, DTA, and TGA indicate that clays from three different localities contain roughly equal proportions of...
C13 and O18 compositions in some fresh-water carbonates associated with ultramafic rocks and serpentinites: Western United States
J. R. O’Neil, I. Barnes
1971, Geochimica et Cosmochimica Acta (35) 687-697
All carbonates associated with the ultramafic rocks and serpentinites of the western United States are shown by their stable isotope ratios to be of near-surface, low-temperature origin. These include vein materials that have been previously classified as hydrothermal. New laboratory and natural data...
Analytical sensitivities and energies of thermal neutron capture gamma rays II
F. E. Senftle, H.D. Moore, D.B. Leep, A. El-Kady, D. Duffey
1971, Nuclear Instruments and Methods (93) 425-459
A table of the analytical sensitivities of the principal lines in the thermal neutron capture gamma-ray spectrum from 0 to 3 MeV has been compiled for most of the elements. A tabulation of the full-energy, single-escape, and double-escape peaks has also been made...
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...
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)...
Determination of silver in soils, sediments, and rocks by organic-chelate extraction and atomic absorption spectrophotometry
T. T. Chao, J.W. Ball, H. M. Nakagawa
1971, Analytica Chimica Acta (54) 77-81
A useful method for the determination of silver in soil, sediment, and rock samples in geochemical exploration has been developed. The sample is digested with concentrated nitric acid, and the silver extracted with triisooctyl thiophosphate (TOTP) in methyl isobutyl ketone (MIBK) after dilution of the...
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...
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...