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Showing papers in "Earth and Planetary Science Letters in 1977"


Journal ArticleDOI
TL;DR: The IUGS Subcommission on Geochronology (FOOTNOTE 4) as discussed by the authors recommended the adoption of a standard set of decay constants and isotopic abundances in isotope geology.

9,474 citations


Journal ArticleDOI
TL;DR: In this article, a strong negative correlation exists between 87Sr/86Sr ratios in oceanic basalt from Iceland and the Reykjanes Ridge, but such a clear correlation does not exist for samples from the Hawaiian Islands.

672 citations


Journal ArticleDOI
TL;DR: In this article, it is suggested that the observed variations are a consequence of dynamic partial melting of a homogeneous mantle source region, which may be generated by processes in the mantle during melting.

627 citations


Journal ArticleDOI
TL;DR: In this article, a detailed analysis of separated phases of several Allende Ca-Al-rich inclusions is reported, which reveal a consistent pattern of large O-16 enrichments in spinel, pyroxene, and sometimes olivine, and small O- 16 enrichment in melilite, feldspathoids, and grossular.

426 citations


Journal ArticleDOI
TL;DR: In the central North Pacific, values decrease from a surface maximum of about 3 nmol/kg to 1.5 nmol /kg in the upper thermocline as discussed by the authors.

387 citations


Journal ArticleDOI
TL;DR: In this article, REE and selected minor and trace elements are compared for present-day volcanic rocks in the Scotia Sea and the results indicate derivation of at least some87Sr from subducted ocean crust.

344 citations


Journal ArticleDOI
TL;DR: In this paper, a ternary plot of MgO FeO(total) Al2O3 was used to distinguish five tectonic environments: ocean ridge and floor, ocean island, continental, orogenic, and spreading center island.

341 citations


Journal ArticleDOI
TL;DR: In this article, a chemical composition of the Archaean mantle is estimated using chemical regularities observed in spinifex-textured peridotites (STP) and high-magnesian basalts.

278 citations


Journal ArticleDOI
Richard Hey1
TL;DR: In this article, the propagation rift model was used to explain the oblique trends of the fracture zones in the Juan de Fuca spreading center, and it was shown that the overall trend of the en echelon fracture zones are oblique to the Blanco transform fault, and the strike of each individual fracture zone is quite different, and is compatible with transform motion between the rigid Pacific and Juande Fuca plates.

267 citations


Journal ArticleDOI
TL;DR: In this article, the authors reexamined available magnetics data from the Tasman Sea and reidentified sea-floor spreading anomalies in the southern portion of the basin, and calculated new finite rotations which descrobe the evolution of basin in terms of a simple two-plate spreading system active between about 82 and 60 m.y.

242 citations


Journal ArticleDOI
TL;DR: In this paper, the ultramafic pyroxenite Angra dos Reis meteorite was estimated to have an internal isochron age of 4.55 plus or minus 0.04 eons.

Journal ArticleDOI
TL;DR: In this article, two models accounting for the concentrations of moderately volatile elements in ordinary chondrites are discussed, one relying on an apparent correlation between ordinary Chondrite/type-I carbonaceous chondrite abundance ratios and ideal solution-condensation temperatures of such elements as Sn, Cu, Li, Na, and Mn to construct a model in which volatiles are lost as gases before nebular condensation or as finely-divided solids that are incompletely agglomerated.

Journal ArticleDOI
TL;DR: In this paper, two cores were taken for radiochemical analysis for radiocarbon and 210 Pb and the data indicate physical disruption of the Mid-Atlantic Ridge section and the date of this disruption is not defined by the data but the restriction of excess 210 pb to the top centimeter of the core implies either that sediment accumulation at this site has only recently resumed or that both the rate of accumulation and rate and depth of bioturbation have been very small since the disrupting event.

Journal ArticleDOI
TL;DR: In this article, the vertical distributions of 210pb and faUlout 137Cs with the distributions of benthic macroinvertebrates, mainly oligochaete worms (Tubificidae) and the amphipod, Pontoporeia affinis, were compared at two locations in southern Lake Huron.

Journal ArticleDOI
TL;DR: In this paper, the metal concentrations and relative proportions are consistent within limits required for metal-rich fluid which produced East Pacific Rise metalliferous sediments, and experiments were carried out as a qualitative indicator of sea-floor precipitation processes.

Journal ArticleDOI
TL;DR: In this paper, a study of the behavior of dissolved Ba during mixing of fresh and marine waters in a classic salt-wedge estuary was made, where much of the mixing was confined within the river channel.

Journal ArticleDOI
TL;DR: In this paper, the authors reconstructed the South Atlantic, the paleodepth of deposition, and the fossil content of these sediments make clear that the Late Cretaceous anaerobic paleoenvironment developed under the influence of an oceanic mid-water oxygen minimum at moderate water depths (500-2500 m), because oxygenated sediments have been observed in the deep basin elsewhere.

Journal ArticleDOI
TL;DR: In this paper, major and trace element data for olivines and rapidly quenched groundmass material separated from eight samples of basaltic rock were presented, and the apparent olivine/liquid distribution coefficients (D) for the elements Mg, Mn, Ni, Co, Cr, Sc, Na, Sm, and Ca have been calculated.

Journal ArticleDOI
TL;DR: In this article, all available Deep Sea Drilling Project results from aseismic ridges have been compiled, and it is shown that at least five major a seismic ridge formations formed close to sea level and have since subsided at rates comparable to that of normal oceanic crust.

Journal ArticleDOI
TL;DR: In this article, a pronounced desorption phenomenon of 226 Ra from sediment was observed in the Hudson River estuary, which is an important source of 226Ra to the oceans.

Journal ArticleDOI
TL;DR: In this article, small 5-20 m high mounds of lithified sediment were discovered in 1972 during a deep-tow survey 20-30 km south of the spreading axis of the Galapagos Rift, at a depth of 2.7 km.

Journal ArticleDOI
TL;DR: In this article, carbon and oxygen isotopic determinations have been made of 29 species of Recent Indian Ocean planktonic foraminifera from 14 core-top samples and as many as 18 species were chosen from a single core top sample.

Journal ArticleDOI
TL;DR: In this article, a spruce branch from the Two Creeks (Wisconsin) forest (∼11,800 B.P.) shows large variations which suggest an unusual hydrologic environment in the area of the tree.

Journal ArticleDOI
TL;DR: In this article, extensive isotopic studies of Pb, Sr and Xe and on chemical abundance measurements of K, Rb, Sr, Ba, Nd, Sm, U and Th for total meteorite and mineral separates of the Angra dos Reis achondrite.

Journal ArticleDOI
TL;DR: Refractory megacrysts of olivine, plagioclase, chromian diopside and Cr-Al spinel are present in samples from several dredge sites and DSDP drill sites in the Atlantic and Pacific Oceans as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, primary crystals of coesite and high sanidine up to 3 mm in greatest dimension have been identified in a grospydite inclusion from the Roberts Victor kimberlite pipe, South Africa.

Journal ArticleDOI
TL;DR: In this article, a map of the heat flux out of the earth's mantle has been prepared by subtracting the heat flow arising in the crust from the surface heat flow, and a new empiricism relating reduced heat flow q* to the mean heat flow of a province q-O, q* ~ 0.6 qo, is used to estimate the reduced heat flux, and the depth parameter b is assigned an average value of 8.5 km.

Journal ArticleDOI
TL;DR: In this article, the effect of cracks initially present in a rock was studied by measuring the full tensor of the coefficient of thermal expansion on two rocks with anisotropic crack distributions.

Journal ArticleDOI
TL;DR: In this paper, it is noted that existing theories predict that fluid convection in the earth, driven by the local geothermal gradient, can occur in areas of relatively high permeability.

Journal ArticleDOI
TL;DR: In this article, the anisotropy of magnetic susceptibility and mean particle size in the silt fraction have been measured in surface sediments and down selected cores from the Vema Channel.