Showing papers in "Earth and Planetary Science Letters in 1968"

TL;DR: In this paper, the fitting of a straight line when both variables are subject to crrors is generalized to allow for correlation of the z and y errors, illustrated by reference to lead isochron fitting.

TL;DR: Partition coefficients for +1, +2, +3 and +4 valent trace ions between alkaline olivine basalt lava and the coexisting ortho- and clinopyroxene phenocrysts from Takashima, North Kyushu, Japan, have been determined by neutron activation analysis as mentioned in this paper.

TL;DR: Combined radioactivity and heat flow measurements in pluionie rocks at 38 localities in the United States define three heat flow provinces; the eastern United States, the Sierra Nevada, and a zone of high heat flow in the western United States which includes the Basin and Range province as discussed by the authors.

TL;DR: In this paper, initial Sr isotopic composition at time of planetary objects formation in solar system and precision measurements for age determination of basaltic achondrites were used for determining the age of a chondrite.

TL;DR: The fractionation factor for oxygen isotope exchange between CO 2 and liquid water has been measured as 1.0409 ± 0.0002, in agreement with the recent value of O'Neil and Epstein this article.

TL;DR: In this paper, the activity of the short-lived 234 Th (half-life = 24 days) was found to be in marked radioactive disequilibrium with respect to the concentration of its parent.

TL;DR: In this paper, the size of fission track etch pits in a natural sample is inferred and the track number reduction can be inferred and therefore, thermalty reduced fission tracks ages may be corrected.

TL;DR: In this paper, age determinations for the stratigraphically oldest exposed lavas in Iceland are reported, and the mean values are 12.5 ± 0.2 m.y.

TL;DR: Fission track dating was applied to a large number of apatites for the first time as mentioned in this paper, and it is easy to identify fission tracks on the (0001) face if one uses the oil immersion technique.

TL;DR: In this paper, a review of the mantle between depths of 200 and 1200 km is presented, in the light of recent experimental investigations on high pressure phase transformations in silicate minerals and on their germanate analogues.

TL;DR: In this article, carbon isotope fractionation factors for graphite, diamond and carbon dioxide exchange between graphite and diamond were calculated and tabulated for various temperatures between 0° and 1000°C.

TL;DR: In this article, the authors show that in young tectonically active continental areas there is a layer of high electrical conductivity at depths of about 20 to 40 km, and that the lower crust in these areas will have the required high conductivity if it is water saturated.

TL;DR: In this paper, the average rate of accumulation of CaCO 3 -free sediment based on the results is about 2 meters/million years, which is at variance with that of Goldberg and his coworkers who find that rates less than one half meter per million years are rather common in major portions of the deep ocean.

TL;DR: In this article, the quality of the data collected from 48 chondrites and 6 achondrites has been assessed using the quality metrics (precision and accuracy) of the chondritic data.

TL;DR: In this paper, a rapid electron probe technique was developed for characterising pyroclastic deposits by the composition of their voleanic glass, and the results showed that the glass composition is remarkably consistent, even though some sample locations are several hundred miles apart.

TL;DR: Paleomagnetic studies of Cretaceous rocks from more than 35 widely separated sites in North America show that the polarity at all but two of the sites is consistently normal, suggesting that the Cretaccous period may be characterized by a magnetic field dominantly of one polarity as mentioned in this paper.

TL;DR: In this paper, a geometrical model is proposed for the recent development of the Vema Fracture valley, which is shown to be consistent with other geological and geophysical observations in this region.

TL;DR: In this paper, lead isotope composition and concentrations of U, Th, Ra, total Pb and Pb 210 in recent volcanic rocks, noting disequilibrium due to chemical fractionations.

TL;DR: In this paper, lead isotope ratios, together with uraninm and lead analyses, are reported for Lower Tertiary (ca. 55-60 m.y.) igneous rocks from Skye.

TL;DR: The isotopic composition of travertines, CO 2, H 2 O and HCO3− from springs, and modern and fossil deposits of Central Italy is reported in this article, which confirms the fact that travertine deposition does not take place at the isotopic equilibrium point.

TL;DR: In this paper, the effects of high pressures (up to 200 kb) and high temperatures (∼1000°C) upon 36 spinels have been investigated in an attempt to define the principal patterns of spinel transformations.

TL;DR: Using the generalised Concordia diagram, a behavior's examination of the U-Th-Pb system in the upper mantle was made in this article. But the authors did not consider the behavior of the Earth itself.

TL;DR: The major portion of the increase in density and elastic properties through the transition region of the upper mantle can be attributed to phase changes as discussed by the authors, however, the density increase in the Earth is slightly greater and the observed increase of the seismic velocities is slightly less than predicted on the basis of phase changes alone.

TL;DR: Excess radiogenic argon in deep sea basalts from crest of East Pacific Rise, noting relation to glass content, was found in this paper, showing that glass content is positively correlated with argon content.

TL;DR: In this paper, the ages of sixteen Mesozoic (Kaoko) basalts and dolerities from the Damaraland igneous province of South-West Africa are presented.

TL;DR: In this article, the uranium distribution in all phases of nine Iherzolite inclusions from the Newer Volcanics of western Victoria has been determined using fission tracks.

TL;DR: In this article, the discovery of fossil charged-particle tracks due to very heavy cosmic ray nuclei (Z > 22) in meteoritic minerals and due to spontaneous fission fragments ( 238 U and 252 Cf) in terrestrial minerals was experimentally studied.

TL;DR: In this article, a sample of the Modipe gabbro of Botswana containing exsolved magnetite particles of maximum dimension less than 17 microns has been separated from a sample made from these grains, and it was found that these particles carry a stable thermoremanence whose characteristics are similar to those of the total rock.

TL;DR: In this article, five layers of rhyolitic ash have been identified in deep-sea cores, taken within about 1000 km east of New Zealand and used for dating of the ash layers.

TL;DR: In this article, regional and local gravity anomaly data are presented for the volcanic island of Lanzarote, the most easterly of the Canary Island group and combined with gravity data from other Canary islands, the present results confirm the gradational position of the islands between a truly oceanic and truly continental environment.