Showing papers in "Earth and Planetary Science Letters in 1970"

TL;DR: In this paper, the carbon isotopes 12C and 13C in the equilibrium system CO2 (gas)-HCO3−(dissolved- CaCO3 (solid) has been measured at temperatures between 20°C and 60°C.

TL;DR: The island arc tholeiitic series as mentioned in this paper is the most dominant in many western Pacific and Atlantic Island arcs and represents the earliest stages in arc evolution. But it is chemically inappropriate to call many of the rocks in island arcs calc-alkaline and they suggest they be known as the "island arc thoeitic series" and they differ from normal thoeiitic features by having a higher percentage of intermediate and acid members and too little normative olivine, for example, to have been in equilibrium with peridotite.

TL;DR: X-ray fluorescence measurements have been made of Rb, K and, to a lesser extent, Sr, Y, Zr and Nb in 35 samples of ocean floor basaltic rocks from four different areas of the oceans.

TL;DR: In this article, rare earth element concentrations in zircons and apatites separated from dacites and granites have been measured, and the rare earth patterns of zirons from granites appear to reflect patterns of the liquid phase at earlier stages of crystallization.

TL;DR: In this paper, a chemical analysis of 112 deep ocean basalts reported in the literature showed systematic chemical trends in major elements with distance from ridge spreading centers, similar to the weathering of single pillows and produce a chemical composition similar to volcanic alkali basalts.

TL;DR: In this paper, the authors report on a dust event which they observed at Barbados on June 12, 1967, and which they have traced to a dust storm covering a large area of West Africa on June 7, 1967; the storm is clearly visible in an ESSA 5 satellite photograph.

TL;DR: In this article, it was shown that theoretically unstable Cr (III) species are often dominant in water in solubility equilibrium with the atmosphere and CrO42− is the major form of trivalent and hexavalent chromium in sea water.

TL;DR: In this article, the formation of olivine and plagioclase from abyssal tholeiite magma has been studied, showing remarkable differentiation, producing high-iron, high-titanium gabbros and aplite in later stages.

TL;DR: The Allende meteorite showed presence of Ca-Al-rich glasses associated with other crystalline phases as mentioned in this paper, which is unusual for a meteorite of the type of Allende.

TL;DR: In this paper, it was shown that diffusion in unconsolidated sediments generally proceeds at rates ranging from half to one twentieth of those applying to diffusion of ions and molecules in free solution.

TL;DR: In this paper, the authors summarized and interpreted magnetic data for the northeast Pacific in terms of sea floor spreading and found that clear areas exist in the disturbed zone and west of the Juan de Fuca Ridge.

TL;DR: In terms of the relative abundance of K, Rb, Cs, Sr and Ba, modern oceanic and island-arc basalts may be viewed as a gradational family ranging from alkali basalt (enriched in these elements) to low-K-tholeiite, such as ocean-floor basalt as mentioned in this paper.

TL;DR: In this article, the equivalence of Eu2+ and Sr interphase partitioning permits the calculation of the Eu 2 and Eu 3+ concentrations in each of any two equilibrated phases of known Sr and rare-earth concentrations.

TL;DR: In this article, petrochemical data on Ordovician igneous rocks from the English Lake District and Wales suggests that they were formed in an island arc/continental margin environment.

TL;DR: In this article, vertical profiles of barium content have been determined in the Atlantic and Pacific Oceans by the isotope dilution method, and the results confirm the hypothesis that barium is incorporated into the remains of organisms in the surface ocean and released to the deep sea as the organic debris sinks toward the bottom.

TL;DR: The isotopic composition of Mg is investigated in meteoritic, lunar and terrestrial feldspar samples and standard reagents using a mass spectrometer with on-line data processing as discussed by the authors.

TL;DR: In this article, the authors found that the deposition rates of iron on the East Pacific Rise are 4-30 times larger than in surrounding areas of the Pacific, suggesting local volcanism to be the source of iron.

TL;DR: The natural deuterium content of organically bound hydrogen shows systematic variations that depend on the origin of the samples as mentioned in this paper, and the hydrogen of both marine and land plants contains several percent less deutricity than the water on which the plants grew.

TL;DR: A Sb-Sr isochron age of 2205 ± 70 my given by a granite gneiss demonstrates that Eburnean granitic and older metamorphic rocks are widespread in southwestern Nigeria.

TL;DR: Rb-Sr internal isochrons of crystalline lunar rocks from tranquility sea for moon age estimation as discussed by the authors were used to estimate the inner isochron of the tranquility sea.

TL;DR: The D/H ratio of unaltered phlogopite of possible mantle or lower crustal origin is −58 ± 18per mil, with no significant variation through space or time over the last 1140 my as discussed by the authors.

TL;DR: In this paper, the authors derived an expression which eliminates the effects of the interfering argon isotopes, and an indication of the degree of interference was given, and the relative amounts of argon, produced during irradiation, were also shown.

TL;DR: In this article, the geochemical and observational aspects of three possible models for the surface of Venus were discussed, and the surface temperature and pressure at which such equilibrium occurs were determined, independent of radar-astronomical and spacecraft observations.

TL;DR: In the North Pacific, manganese is apparently incorporated into sediments in association with clay or a related phase; in other ocean basins, no generalizations can be drawn from the data presented here as discussed by the authors.

TL;DR: Boron is preferentially partitioned into the liquid phase in high-temperature reactions of basaltic rocks and sea-water as mentioned in this paper, and it is used to prevent peridotite serpentinization.

TL;DR: In this paper, twenty new potassium-argon age determinations on mineral separates from granitic rocks of the Andes of northern Chile, between latitudes 26° and 29°South, indicate the existence of at least five major intrusive episodes: Permian, Lower Jurassic, Middle Cretaceous, Lower Paleocene and Upper Eocene.

TL;DR: In this paper, the ages of 16 submarine basalts dredged from 5 seamounts in the Western Pacific area are presented, and the ages range from 30 my to 80 my.

TL;DR: A number of concordant K Ar ages in the range 100 to 105 my have been measured on samples from the tholeiitic Rajmahal Traps of India.

TL;DR: In this article, a preliminary petrological description is presented of rocks obtained where the Mid-Atlantic Ridge is intersected by the Chain, Romanche and St. Paul fracture zones and from unfractured sections of the Ridge between 6° and 8°N.

TL;DR: Apollo 12 lunar rock 12013 petrologic and mineralogic characteristics, discussing data on isotopic Xe and Gd composition, were discussed in this paper, with a focus on isotope Xe.