Showing papers in "Earth and Planetary Science Letters in 1986"

TL;DR: In this paper, the authors proposed a new constraint on mantle composition: the differentiated part of the mantle, chemically depleted after separation of the major portion of the continental crust, was subsequently internally rehomogenized.

TL;DR: In this article, the authors used isotope dilution mass spectrometers to determine 238U,234U and232Th concentrations in seawater using a 233U236U double spike to correct for instrumental fractionation.

TL;DR: In this paper, the Deccan continental flood basalts in India have been considered and it was suggested that volcanic activity may have lasted less than 1 Ma, thus possibly ranking as one of the largest volcanic catastrophes in the last 200 Ma.

TL;DR: In this paper, an analysis of mid-ocean ridge basalt (MORB) glasses was performed and the redox states of MORB magmas with respect to geography and chemistry were determined.

TL;DR: In this article, a change occurred in the climatic response of northern hemisphere ice sheets and the high-latitude North Atlantic Ocean to orbitally controlled variations in insolation during the middle Pleistocene.

TL;DR: In this paper, a geodynamic model based on changes of the type of subduction of the Indian oceanic crust beneath the Lhasa block, for the period 120-40 Ma, is proposed to account for the abundance, age, and magmatic affinity of the volcanic products.

TL;DR: In this article, the authors discuss the evidence for deep crustal metamorphism during continental extension, the pressure-temperature-time (P-T-t) paths associated with such metamorphisms, and, finally, a number of examples of deep-crusted terrains which may have been associated with extensional tectonics.

TL;DR: In this article, a set of submarine basaltic glasses dredged from a variety of locations contain 0.400 ppm dissolved CO 2, measured using the infrared spectroscopy technique.

TL;DR: In this paper, the depeletion of chalcophile and siderophile elements in the mantle was studied and it was suggested that the crust formation involves nonmagmatic and magmatic processes.

TL;DR: This article showed that small-scale convection increases the amount of heat transported vertically into the rift and laterally out of it, and that such convection can produce uplift at least twice as great as would be produced by lateral conduction alone.

TL;DR: The stabilization of continental lithosphere to form cratons is accomplished by volatile loss from the upper mantle during magmatic events associated with the formation of continental crust as mentioned in this paper, which elevates the solidus and increases the stiffness of the mantle residuum, thereby imparting resistance to subsequent melting and deformation.

TL;DR: In this article, the vertical distributions and horizontal surface transects of dissolved and particulate Al at several locations in the Pacific Ocean are presented, and it is shown that the primary source of dissolved Al to the surface waters of the central Pacific is from eolian input.

TL;DR: In this article, the length distribution of fission tracks in apatites from deep boreholes was measured and it was shown that the lengths of the longest tracks remain essentially constant at all stages of natural annealing observed in the boreholes.

TL;DR: In this paper, the authors used the diffusion rates for oxygen as a function of temperature, the cooling rate of the rock, the mineral grain sizes, and the mode of a rock to estimate the apparent 18O16O temperature in a single sample of feldspars, quartz, and hornblende.

TL;DR: In this article, the age and origin of leucogranites from the High and Tethys Himalaya, and two country-rock gneisses were investigated by U Pb dating of zircon fractions and single grains, and fractions of monazite.

TL;DR: The origin of 1.9-1.7 Ga crust in Europe, Greenland and North America can be evaluated using Nd and other isotopic information as mentioned in this paper, and the results document major crustal growth during Proterozoic time.

TL;DR: In this article, the authors present an analysis of lithospheric strength variations across the Mediterranean continental margin and predict a characteristic strength profile at continental margins, which consists of a marked increase in strength seaward of the hinge zone and a strength minimum landward of a hinge zone.

TL;DR: In this article, it was shown that the seismic velocity distributions in the mantle between 400 and 650 km are inconsistent with Anderson's hypothesis that this region is of eclogitic composition.

TL;DR: In this article, a new model of the opening of the Japan Sea is proposed based on the synthesis of both on-land and offshore structural data, which gives new constraints about the structural evolution of the system.

TL;DR: The Hangingwall Basalt at Kambalda, Western Australia, contains zircons that have been shown by ion microprobe analyses to have very high U and Th contents and a wide variety of crystallization ages.

TL;DR: In this paper, the authors calculated the equilibrium oxygen fugacities of basaltic glassy lavas and compared them to NNO at the same temperature (1200°C) and showed that the relativefO2, ΔNNO becomes essentially independent of temperature.

TL;DR: A Pb Sr Nd isotope study of South West and East Indian Ridges confirms that the Indian Ocean belongs to a specific regional isotopic domain, as previously suggested by the results from islands of this ocean.

TL;DR: In this paper, the effect of the Icelandic mantle plume on helium isotope rn1ios is observable along the entire length of the Reykjanes Ridge (R = 11−16.1 R A ) and to 70°N on the Kolbeinsey Ridge ( R = 10.3−12 R A ).

TL;DR: In this article, the relationship between density distributions in oceanic lithosphere and the depth of melting at spreading centres is investigated by calculating the mineral proportions and densities of residual mantle depleted by extraction of melt fractions.

TL;DR: The relationship between the Agrand number and the vertically-integrated strengths of the lithosphere and the thermal regime of the uppermost mantle and the stress state in the upper crust is analyzed in this paper.

TL;DR: The DSD Hole 504B is the deepest basement hole in the oceanic crust, penetrating through a 571.5 m pillow section, a 209 m lithologic transition zone, and 295 m into a sheeted dike complex.

TL;DR: Basalts dredged from ridge axes within 70 km of the Indian Ocean triple junction in the western Indian Ocean have many geochemical and petrologic characteristics in common with depleted mid-ocean ridge basalts (MORBs) from the Atlantic and Pacific as discussed by the authors.

TL;DR: In this paper, the authors suggest that the uplift of the Transantarctic Mountains and the subsidence of the Ross Embayment are a result of passive rifting governed by a fundamental structural asymmetry defined by a shallow crustal penetrative detachment zone that dips westward beneath the TMT.

TL;DR: In this paper, the authors analyzed precipitation collected in continuously open containers for about a year at seven sites around the United States for 10Be,90Sr,210Pb and238U.

TL;DR: The authors showed that apatite fission track length information can be interpreted as the result of partial to complete resetting of the older ages by a widespread thermal event at about 80-100 Myr.