Showing papers in "Earth and Planetary Science Letters in 1972"

TL;DR: In this paper, the isotopic composition of Pb and the elemental concentration of U, Th and Pb were measured on total rock samples 14053, 14073 and 14310.

TL;DR: The application of 210Pb dating to an inshore marine deposit off the California coast has been successful as mentioned in this paper, and the amounts of unsupported210Pb annually accumulated in the Santa Barbara sediments are much greater than those from lake and glacial deposits and than the amount produced through the decay of radium in the overlying water column.

TL;DR: In this article, it was shown that the observed density trends in the inner solar system need not be the result of special fractionation processes, and that the densities of the terrestrial planets may be direct results of simultaneous application of both physical and chemical restraints on the structure of the nebula, most notably the variation of temperature with heliocentric distance.

TL;DR: In this paper, the ages of apatites from the Swiss and Italian Alps were used to define the time when these rocks cooled down to temperatures to 125 ± 20°C.

TL;DR: In this article, the authors give a linear equation that holds up to molality of 6 in pure and mixed salt solutions, where M is the molality value on a concentration scale.

TL;DR: Basalts dredged from the ocean basin behind the Mariana Island arc range from (subalkaline) olivine tholeiite to olivines basalt and have higher contents of the dispersed elements (K, Rb, Cs, Sr, Ba, REE) than do typical spreading-ridge basalts as mentioned in this paper.

TL;DR: Barium saturation in the sea water column has been compared to the barium concentrations in the eastern Pacific Ocean and in pore waters filtered from sediments containing marine barite in this paper, showing that the observed increase of barium concentration with depth in the Pacific is not the result of simple chemical equilibrium between solid barite and sea water of differing temperature and pressure.

TL;DR: The rate of solution of a single biogenic opal test is a function of solution temperature, degree of saturation, available surface area of the test and any coating or protective layer the test may have as mentioned in this paper.

TL;DR: Cosmic ray-produced neutron equilibrium spectra are calculated for a variety of lunar surface compositions in this article, and the spectra production rates of 80Kr, 82kr, 114Cd, 131Xe, 150Sm, 152Sm, 156Gd, 158Gd and 187Re are determined and compared with measurements.

TL;DR: In this article, it was shown that phase transformations play a major role in driving the lithosphere slab into the mantle at depths greater than 300 km, and also control the stress distribution within the slab.

TL;DR: The known geology of the Gulf of California region indicates that a trench, andesite chain, and ignimbrite province co-existed in Mid- to Late Tertiary time in the same tectonic pattern as observed in trench-arc systems.

TL;DR: In this paper, the kinetics of racemization of isoleucine in a calcareous sediment have been investigated in detail over the temperature range 100°−148°C.

TL;DR: In this paper, the authors studied the relationship between the K 2 O versus SiO 2 value in volcanic rocks of the active volcanoes of the Hellenic and Calabrin arcs and the depth of the underlying earthquakes.

TL;DR: Satellite-fixed magnetic and bathymetric data confirm the presence of a spreading center in the east Scotia Sea behind the South Sandwich island arc and trench as discussed by the authors, which is slightly asymmetric, favouring the eastern, island arc side, and the total spreading rate has increased from 5 to 6 cm/yr 4 Ma ago, to 7 to 9 cm/r at present.

TL;DR: In this paper, the isotopic composition of atmospheric CO in the northern hemisphere has been studied and the most likely nature of these sources is discussed and the production rates estimated. But the isotope pattern is different from that for CO from automobile engine combustion, whether compared to combustion in the same region as the air sample or to an estimated world average.

TL;DR: In the absence of convincing magnetic anomaly information, topographic profiles have been used to infer the tectonic history of the East Pacific Rise between 5°S and 20°S as mentioned in this paper.

TL;DR: In contrast to the North Atlantic, there is a very large gradient of dissolved O2 in the vertical profile of North Pacific Deep Water; however, if themean deep-water O2 concentration is compared with the uniform value in North Atlantic Deep Water, the O2 and ΣCO2 differences in North Pacific and North Pacific deep water are essentially equimolar at 160 μm/kg.

TL;DR: In this paper, the coexisting liquid and solid phases formed upon partial melting of a garnet lherzolite inclusion from kimberlite and a spinel LH inclusion from tuff have been analyzed with the electron probe microanalyser.

TL;DR: In this paper, the authors used both P-wave first motions and the radiation pattern of Rayleigh waves in the focal mechanisms determinations, the uncertainty in strike is held to about ± 10°.

TL;DR: In this paper, a simple two-stage model was proposed in which the lunar crust is generated by the addition of magmatic material enriched in Pb relative to both U and Th (without U-Th fractionation).

TL;DR: In this article, the authors used the amount of racemization of isoleucine to estimate the age of two fossil bones, one from a cave on the Island of Mallorca (Spain) and the other from the core of a deep-sea manganese nodule.

TL;DR: The lower portions of the volcanic sequence of some Archaean greenstone belts include members with crystallized from ultramafic liquids extruded at the earth's surface at 1600-1650°C, which implies more catastrophic conditions of mantle melting than obtained in Palaeozoic, Mesozoic or Recent crustmantle dynamics as discussed by the authors.

TL;DR: In this article, a pneumatically operated piston corer was used for magnetic investigations of sediment from Lake Windermere, and the results from the Pleistocene Narita bed (Japan) were compared with those from Lake windermere.

TL;DR: Paleomagnetic examination of a 1-kg specimen of the Allende meteorite has revealed the existence of natural remanent magnetization of constant direction and moderate intensity (3.0 × 10 −4 emu/g) as discussed by the authors.

TL;DR: The mechanism of crystal slip in olivine in peridotite xenoliths from alkalic basalts has been investigated by highvoltage (up to 1 MeV) electron petrography as discussed by the authors.

TL;DR: In this article, high concentrations of dissolved Mn in pore waters of surface sediments and decreasing concentrations with depth are explained by migration, re-precipitation and reaction of Mn oxides during burial at redox boundaries.

TL;DR: A detailed detailed barium profile has been measured at Geosecs III, off Tonga, in the southwest Pacific as mentioned in this paper, showing a smooth increase from the surface values of 4.7 μg/kg to a deep maximum of 18.4 μg/ kg at 2.974 km.

TL;DR: The determination of barium and strontium directly from sea water by isotope dilution mass spectrometry proves to be an efficient, precise, and virtual blank free procedure as discussed by the authors.

TL;DR: In this article, the amphibole stability limit was shown to increase in temperature when the mole fraction of H 2 O in the fluid phase in equilibrium with the melt was decreased from 1.0 to 0.5; these experiments imply that there is an isobaric temperature maximum of stability.

TL;DR: The early stages of calc-alkalic intermediate volcanism over much of the central and southern parts of the western United States about 37 my ago cannot be adequately explained by a steady-state subduction model, and may reflect an abrupt change in the relative movements of the North American and Farallon plates and the underlying asthenosphere.