Effect of sample inhomogeneity in K Ar dating
J. C. Engels, C.O. Ingamells
1970, Geochimica et Cosmochimica Acta (34) 1007-1017
Error in K-Ar ages is often due more to deficiencies in the splitting process, whereby portions of the sample are taken for potassium and for argon determination, than to imprecision in the analytical methods. The effect of the grain size of a sample and of the composition of a contaminating...
Paleomagnetic secular variation study of lavas from the Massif central, France
Richard R. Doell
1970, Earth and Planetary Science Letters (8) 352-362
The angular standard deviation of virtual geomagnetic poles determined from a paleomagnetic study of 31 Brunhes-age lava flows from France has been obtained. The value, referred to the axial dipole (geographic axis), is 15.2° with 95% confidence limits of 18.4° and 12.9°....
Cummingtonite: A reversible, nonquenchable transition from P21/m to C2/m symmetry
C.T. Prewitt, J. J. Papike, M. Ross
1970, Earth and Planetary Science Letters (8) 448-450
Cummingtonite from the Gouverneur, New York, talc district (Sample No. U.S.N.M. 115046) with the composition, (Ca0.36Na0.06Mn0.96Mg0.57) Mg5Si8O22 (OH)2, unit cell parametersa = 9.550 ± 0.001, b = 18.007 ± 0.003, c = 5.298 ± 0.001Å, β = 102°39′ ± 1′, and space...
Aeromagnetic map of the Menominee-Northland area, Dickinson, Marquette, and Menominee Counties, Michigan, and Marinette County, Wisconsin
Water Resources Division, U.S. Geological Survey
1970, Geophysical Investigations Map 711
No abstract available....
Lithium metaborate flux in silicate analysis
C.O. Ingamells
1970, Analytica Chimica Acta (52) 323-334
Lithium metaborate is an effective flux for silicates and other rock-forming minerals. The glass resulting from fusion is mechanically strong, reasonably nonhygroscopic, and is readily soluble in dilute acids. These characteristics lead to its use in X-ray spectrography and in methods which require whole-rock solutions,...
Winds over saltcedar
T. E. A. Van Hylckama
1970, Agricultural Meteorology (7) 217-233
An analysis of hourly wind speeds above and within a stand of saltcedar near Buckeye, Arizona, reveals that in 90% of all observed cases, the wind profiles above the stand can be represented by the simple logarithmic equation: uz=u*k1n">uz=u*k1n (zz0)">zz0) where...
Strontium isotopes in some Cenozoic lavas from Oregon and Washington
C. E. Hedge, R.A. Hildreth, W.T. Henderson
1970, Earth and Planetary Science Letters (8) 434-438
The87Sr/86Sr ratios have been determined in 22 volcanic rocks from Oregon and Washington. The emphasis of the study was on andesites and dacites, but several basalts were included. Most of the samples have a very limited range in strontium isotopic composition...
Effects of oil development in Arctic America
J. C. Reed
1970, Biological Conservation (2) 273-277
Large and important discoveries of petroleum were made in northern Alaska in 1968. The reserves were estimated then to be perhaps as much as ten thousand million barrels. Subsequent exploration has shown the resources to be much greater than was estimated earlier. Many...
Isotopic investigations of xenoliths and host basalts from the Honolulu volcanic series
J. R. O’Neil, C. E. Hedge, E.D. Jackson
1970, Earth and Planetary Science Letters (8) 253-257
Oxygen, carbon and strontium isotope ratios point to a ground-water origin for the carbonates found in Hawaiian Volcanic Series rocks. Strontium isotope ratios in the xenoliths and host basalts indicate a genetic relationship between them....
Strontium isotopes in Quaternary basalts of southeastern California
Z. E. Peterman, I. S. E. Carmichael, A. L. Smith
1970, Earth and Planetary Science Letters (7) 381-384
Strontium isotopic variations (87Sr/86Sr of 0.7029 to 0.7052) in Quaternary basalts of southeastern California, USA, are not readily explained by assimilation of crustal material similar to that contained as xenoliths in the basalt. Isotopic differences between chrome diopside (0.7016) and olivine...
Sources of geochemical standards-II
F.J. Flanagan
1970, Geochimica et Cosmochimica Acta (34) 121-125
A revised and enlarged list of rock, mineral, ore, industrial product, counting, and isotopic standards of interest to those in geochemistry and geology is presented. Samples in process are also included. Sources from which the samples may be obtained are listed.<ul id="issue-navigation" class="issue-navigation...
Atmospheric collection of debris from the Revelstoke and Allende fireballs
M. H. Carr
1970, Geochimica et Cosmochimica Acta (34) 689-700
In two separate events, Revelstoke and Allende, the air through which a fireball had been observed to pass was sampled for meteoritic debris. Particulate matter was collected on fibrous filters, which were mounted on aircraft and flown downwind from the site of the...
Crystallography of some lunar plagioclases
D. B. Stewart, D.E. Appleman, J.S. Huebner, J. R. Clark
1970, Science (167) 634-635
Crystals of calcic bytownite from type B rocks have space group I1 with c ≈ 14 angstroms. Bytownite crystals from type A rocks...
Lunar troilite: Crystallography
H. T. Evans Jr.
1970, Science (167) 621-623
Fine, euhedral crystals of troilite from lunar sample 10050 show a hexagonal habit consistent with the high-temperature NiAs-type structure. Complete three-dimensional counter intensity data have been measured and used to confirm and refine Bertaut's proposed low-temperature crystal structure....
Chemical indicators of subsurface temperature applied to hot spring waters of Yellowstone National Park, Wyoming, U.S.A.
R.O. Fournier, A.H. Truesdell
1970, Geothermics (2) 529-535
Under favorable conditions the chemistry of hot springs may give reliable indications of subsurface temperatures and circulation patterns. These chemical indicators can be classified by the type of process involved:IndicatorDominant ProcessThe silica...
Age of the moon: An isotopic study of uranium-thorium-lead systematics of lunar samples
M. Tatsumoto, J.N. Rosholt
1970, Science (167) 461-463
Concentrations of U, Th, and Pb in Apollo 11 samples studied are low (U. 0.16 to 0.87; Th, 0.53 to 3.4; Pb, 0.29 to 1.7, in ppm) but the extremely radiogenic lead in samples allows radiometric dating. The fine dust and the breccia have a concordant age of 4.66 billion...
Lunar rock compositions and some interpretations
A.E.J. Engel, C.G. Engel
1970, Science (167) 527-528
Samples of igneous "gabbro," "basalt," and lunar regolith have compositions fundamentally different from all meteorites and terrestrial basalts. The lunar rocks are anhydrous and without ferric iron. Amounts of titanium as high as 7 weight percent suggest either extreme fractionation of lunar rocks or an unexpected solar abundance of titanium....
Photogeologic and thermal infrared reconnaissance surveys of the Los Negritos-Ixtlan de los Hervores geothermal area, Michoacan, Mexico
Valle R. Gomez, J. D. Friedman, S.J. Gawarecki, C.J. Banwell
1970, Geothermics (2)
New techniques, involving interpretation of panchromatic, ektachrome and ektachrome infrared aerographic photogaphs and thermographic infrared imagery recording emission from the earth's surface in middle and far infrared wavelengths (3–5μm and 8–14μm), are being introduced in geothermal investigations in Mexico to identify outstanding structural and geologic features in a rapid and...
Sulfur isotope distribution in solfatares, Yellowstone National Park
R. Schoen, R. O. Rye
1970, Science (170) 1082-1084
Sulfur isotope data on hydrogen sulfide, native sulfur, and sulfates from acid hot-spring areas at Yellowstone National Park suggest that hydrogen sulfide oxidizes to sulfur analogically, whereas sulfur undergoes biological oxidation to sulfuric acid. An exception occurs at Mammoth Hot Springs where hydrogen sulfide apparently undergoes biochemical oxidation to sulfur....
A new technique for pumping hydrogen gas
I. Friedman, K. Hardcastle
1970, Geochimica et Cosmochimica Acta (34) 125-126
A system for pumping hydrogen gas without isotopic fractionation has been developed. The pump contains uranium metal, which when heated to about 80°C reacts with hydrogen to form UH3. The UH3 is heated to above 500°C to decompose the hydride and regenerate the hydrogen....
Deuterium: Natural variations used as a biological tracer
J.D. Gleason, I. Friedman
1970, Science (169) 1085-1086
The suggestion is made that isotope tracing be carried out by monitoring the natural variations in deuterium concentrations. As an example, the natural variations in deuterium concentrations between food and water collected in Illinois and food and water collected in Colorado were used to determine the residence time of water...
Thermoluminescence of lunar samples
G. B. Dalrymple, Richard R. Doell
1970, Science (167) 713-715
Appreciable natural thermoluminescence with glow curve peaks at about 350 degrees centigrade for lunar fines and breccias and above 400 degrees centigrade for crystalline rocks has been recognized in lunar samples. Plagioclase has been identified as the principal carrier of thermoluminescence, and the difference in peak temperatures indicates compositional or...
Latitudinal gradients in tertiary molluscan faunas of the Pacific coast
W.O. Addicott
1970, Palaeogeography, Palaeoclimatology, Palaeoecology (8) 287-312
Tertiary molluscan faunas of the middle latitudes of the marginal eastern North Pacific are characterized by warm-water taxa whose descendants now live in more southerly latitudes. A series of profiles in which cumulative percentages of warm-water faunal elements are plotted against latitude show progressive northward decreases in the percentage of...
Missile impacts as sources of seismic energy on the moon
G.V. Latham, W.G. McDonald, H. J. Moore
1970, Science (168) 242-245
Seismic signals recorded from impacts of missiles at the White Sands Missile Range are radically different from the signal recorded from the Apollo 12 lunar module impact. This implies that lunar structure to depths of at least 10 to 20 kilometers is quite different from the typical structure of the...
Arsenic in detergents: Possible danger and pollution hazard
E.E. Angino, L.M. Magnuson, T.C. Waugh, O.K. Galle, J. Bredfeldt
1970, Science (168) 389-390
Arsenic at a concentration of 10 to 70 parts per million has been detected in several common presoaks and household detergents. Arsenic values of 2 to 8 parts per billion have been measured in the Kansas River. These concentrations are close to the amount (10 parts per billion) recommended by...
