Showing papers in "Earth and Planetary Science Letters in 1982"

TL;DR: In this article, the authors applied the Ti/V plot to published data on ophiolites from a variety of postulated settings and in general supported the conclusions of previous investigators.

TL;DR: In this article, the authors propose a model for the origin of hot-spot volcanism, where oceanic crust is returned to the mantle during subduction and sinks into the deeper mantle and accumulates at some level of density compensation, possibly the core-mantle boundary.

TL;DR: In this paper, a simple idealized model based on sized magnetite samples is proposed to explain the use of the χARMversusχ plot for detecting relative grain-size changes in the magnetic content of natural materials.

TL;DR: In this article, a set of discrimination diagrams have been derived from a statistical study of the Ti, Cr, Ca, Al and Na contents of over 706 analyses of calcic clinopyroxene phenocrysts from recent volcanic rocks of various magmatic types from various tectonic settings.

TL;DR: A detailed study of the evolution of the northern Himalayan orogeny has been carried out using petrographic, geochemical and isotope analytical techniques in the Ladakh region of India as discussed by the authors.

TL;DR: In this article, the initial Nd and Sr isotopic composition has been determined in S- and I-type granites from the Paleozoic Berridale and Kosciusko Batholiths of southeast Australia.

TL;DR: In this paper, an alternative approach is presented, formally relating unknown ages of samples to known ages of standards, either by direct comparison of standard and sample track densities, or by repeated calibration of a glass against age standards.

TL;DR: In this article, the authors examined teleseismic, local seismic, surface faulting and geomorpbological data and found that the first and second major destructive earthquakes in the eastern part of the Gulf of Corinth in February' and March 1981 activated major north-dipping normal faults.

TL;DR: In this article, the authors proposed that magnetic anomalies south of Australia and along the conjugate margin of Antarctica that were originally identified as anomalies 19 to 22 may be anomalies 20 to 34.

TL;DR: In this paper, the melting phase relations of an augite-olivine high-magnesian andesite and a basalt from the Miocene Setouchi volcanic belt in southwest Japan have been studied under water-saturated, water-understandable and under anhydrous conditions.

TL;DR: High-magnesian andesites of middle Miocene age occur in southwest Japan, forming an obvious volcanic belt as mentioned in this paper, and they are relatively aphyric (phenocrysts <10 vol.%), and the phenocrysts of magnesian olivine (∼Fo88) are in equilibrium with the host highmagnesians andesite magmas on the basis of the Fe-Mg exchange partitioning.

TL;DR: Basement intersected in DSDP holes 525A, 528 and 527 on the Walvis Ridge consists of submarine basalt flows and pillows with minor intercalated sediments as mentioned in this paper.

TL;DR: In this article, it was shown that the crust as a whole is a sink for K, Rb, Cs, and probably U, with yearly fluxes of 1.1 × 1013, 2.6 ×1010, 6.0 × 108 and 1.0×109g, respectively.

TL;DR: Pb, Nd and Sr isotope compositions of oceanic basalts have been used to identify recycled components of continent derivation in the mantle as discussed by the authors, and they have been determined for back-arc basalt glasses from the Scotia Sea and Parece Vela and West Philippine Basins, in addition to basalts from South Sandwich Islands, Ascension, St. Helena and Tristan da Cunha.

TL;DR: The Cenozoic volcanic rocks of eastern China are subalkalic to alkalic basalts erupted in an early Tertiary back-arc rift environment and from scattered late-Tertiary and Quaternary volcanic centers in a continental area crossed by active faults, driven by subduction of the Pacific plate and the collision of India and Eurasia as mentioned in this paper.

TL;DR: In this paper, the metal-nutrient relationship observed for nickel and cadmium in the deep ocean is continued at the interface between seawater and oxidizing pore water.

TL;DR: In this article, a set of 35 basaltic glass samples dredged from the Mid-Atlantic Ridge between 28° and 53°N latitude were analyzed and the helium concentrations and helium isotopic ratios were determined.

TL;DR: In this paper, a kinematic model combining two orthogonal shear components is proposed to explain the observed strain trajectories in the Variscan orogenic belt in France.

TL;DR: In this article, the authors used the distribution of ages along the Comores-Madagascar chain in conjunction with existing age data for the Reunion-Mascarene Plateau hotspot track to model the absolute motion of the Somali plate for the last 10 m.y.

TL;DR: In this paper, the authors present data on the abundances, sizes and crustal age for all volcanoes (volcanic islands and seamounts) which appear on published bathymetric charts of the Pacific Ocean.

TL;DR: In this article, the Deccan flows at Mahabaleshwar are divisible into a lower and an upper group, based on Nd and Sr isotopic ratios, which define two correlated trends.

TL;DR: In this paper, mineralogical and isotopic variations observed in altered glassy and crystalline rocks from the East Pacific Rise and the Mid-Atlantic Ridge provide information about the temperatures of alteration and seawater/rock ratios for various hydrothermal regimes within the oceanic crust.

TL;DR: In this article, a thermodynamic approach employing metal sulfide formation and class specific sulfidic ligand complexation to generate equilibrium profiles adequately describes the solubility of iron, copper, and cadmium.

TL;DR: Oxygen isotope analyses of planktonic foraminifera from an anoxic basin (Orca Basin) in the northwestern Gulf of Mexico record a negative isotopic anomaly of 3.6 as discussed by the authors.

TL;DR: In this article, the pore waters from the MANOP siliceous and calcareous ooze sites in the central Pacific Ocean were recovered by shipboard squeezing and centrifuging techniques and an in situ harpoon sampler.

TL;DR: The case for a single supercontinent in Proterozoic times is examined in the context of a modified reconstruction with the Precambrian shields collectively comprising a primary lens-shaped body of crust, and it is shown that palaeopoles from the major shields conform to a single narrow path from ca. 2600 to 570 Ma.

TL;DR: The results of integrated isotopic model calculations show that observed local isotopic and trace element variations within the Arequipa and Barroso volcanic groups of southern Peru are best fit by a simple model involving shallow or intermediate depth crustal assimilation of Charcani gneiss (or an equivalent rock) accompanied by dominantly plagioclase fractional crystallization as mentioned in this paper.

TL;DR: The basaltic rocks from the central and southern islands of the New Hebrides-Aneityum, Tanna, Erromango, Efate, Emae, Tongoa and Epi, have geochemical features typical of island arc volcanics.

TL;DR: Particle mixing rates have been determined for 5 South Atlantic/Antarctic and 3 equatorial Pacific deep-sea cores using excess 210 Pb and 32 Si measurements using a steady state vertical advection diffusion model.

TL;DR: In this article, Nd and Sr isotope determinations on late Precambrian to early Palaeozoic igneous and sedimentary rocks from the Arabian Shield are used to investigate the proportion of reworked older crust, and the rate at which new crust was generated during the Pan African event.