Showing papers in "Lithos in 1987"

TL;DR: In this paper, the ages of six plutonic units from the Karakorum axial batholith (Darkot Pass, Ghamu Bar, Batura and Hunza units) and two of northern Kohistan (Gindai and Nomal plutons) are defined and compared based on field data and analyses of up to 78 samples.

TL;DR: Inclusions of sulphides are common in clinopyroxene megacrysts and Al-augite pyroxenite xenoliths in undersaturated continental basalts.

TL;DR: In this article, the authors analyzed manganese nodules and 17 associated sediments from the equatorial and S.W. Pacific regions of the world and found that the rare earth elements (REE) abundance in the nodules was higher in equatorial nodules than in their associated equatorial Pacific sediments.

TL;DR: In this article, the Tertiary granites of North Yemen belong to alkaline or peralkaline associations of A-type and the textural characteristics indicate that the granites are either hypersolvus or subsolvervus.

TL;DR: The late Quaternary phonolitic pumice deposits of Tenerife, Canary Islands, are the product of a periodically-tapped, periodically-replenished, zoned alkaline magma system as mentioned in this paper.

TL;DR: A depleted mantle source was inferred for the mafic lavas from their 87Sr/86Sr (0.70342-0.68376) and 143Nd/144Nd (0.,51278- 0.51288) ratios as mentioned in this paper.

TL;DR: In terms of morphology, there are four major types of calcic amphibole; massive, prismatic, finely acicular and asbestos as mentioned in this paper, and they have been examined by optical microscopy, X-ray diffraction, scanning and transmission electron microscopy and electron probe microanalysis.

TL;DR: In this article, the major and trace-element distribution in the metabasites of the Nevado-Filabride Complex (Betic Cordilleras, Spain) suggests that the whole mafic-ultramafic association represents a dismembered ophiolitic sequence.

TL;DR: In this paper, zircon UPb and total-rock (TR) and mica methods were used to estimate the minimum age of the Irindina supracrustal assemblage.

TL;DR: In this paper, the ages of basalt basalt lavas from Vestfjella, Dronning Maud Land, Antarctica have been investigated and the majority of the basalts are tholeiites.

TL;DR: Lavas from three seamounts along the Hawaiian Ridge are petrographically and geochernically similar to lavas from the Hawaiian Islands as discussed by the authors, which indicates that the source composition and petrogenesis of lavas along the Hawaii chain are very consistent.

TL;DR: In this paper, the authors investigated 35 samples including all of the above rock types on 100 polished thin sections for Cu-Fe-Ni-S mineral assemblages and found that most of them contain traces of CuFeNi sulfides, native metals and locally Ni arsenide.

TL;DR: In this paper, the transition zone between the anorthositic-noritic rhythmic units and the mangeritic unit of the Bjerkreim-Sokndal layered lopolith (southwest Norway) is characterized by thick layers of ultramafic rock (UML), interleaved with norites in the lower part and mangerite in the upper part.

TL;DR: In this article, the Sisimiut (Holsteinsborg) area of West Greenland can be grouped into three main types each showing characteristic mineral parageneses: Micaceous kimberlites contain macrocrysts and phenocrysts of olivine and phlogopite, leucite, diopside, perovskite, and spinels.

TL;DR: The Barrington Tops Batholith (BTB) is a shallow level intrusive complex of Permian age (262 Ma) in Zone A of the New England Fold Belt, northern New South Wales.

TL;DR: A suite of 39 spilitic basalts and andesites of Bajocian age was analyzed for the major elements and Li, Rb, Sr, Ba, Sc, V, Cr, Co, Ni and seven REE, Hf, Ta and Th were analyzed in 20 samples, Sr and O-isotope ratios have been determined for selected whole-rock samples as discussed by the authors.

TL;DR: The Eiksunddal eclogite complex is one of the larger group B (country-rock) Eclogites within the Western Gneiss Region (WGR) of Norway as mentioned in this paper.

TL;DR: In this paper, the authors show that fractional crystallization results in increasing SiO2, Na2O, Zr, Nb, Ce, Rb, Th, Y, LREE, Zn, Pb, and REE with differentiation.

TL;DR: The Somerset Dam intrusion probably represents a small, relatively shallow, subvolcanic magma chamber as discussed by the authors, and the parent magma is inferred to have been a high-alumina olivine tholeiite.

TL;DR: In this paper, the conditions of formation and origin of the fluids responsible for the crystallization of these unusual minerals are discussed, and several arguments suggest that their origin is not hydrothermal, but possibly deuteric.

TL;DR: A detailed electron microprobe study has been made of magnetite grains from magnetitite layer 1 of the upper zone of the Bushveld Complex, in order to establish if there is any evidence for postcumulus processes having affected magnetite compositions as discussed by the authors.

TL;DR: Zircons separated from monzonoritic rocks and quartz mangerites (igneous and metamorphic) have been studied for various mineralogical, chemical and physical properties (colour, zoning, presence of core, U distribution, morphology, lattice parameters, thermoluminescence) as mentioned in this paper.

TL;DR: In this paper, alluvial nuggets of PGE alloys from the rivers Miessijoki, Sotajoki, Puskuoja, Palsinoja and Ivalojoki at Kolmosenkoski rapids and from the Harkaselka area have been investigated with a microprobe and a scanning electron microscope.

TL;DR: The Thorsmork ignimbrite, southern Iceland, contains a suite of granophyre xenoliths displaying magmatic or high-temperature sub-solidus mineral assemblages.

TL;DR: In this paper, the results from the proposed method support the previous suggestion that the palaeogeotherm in the upper mantle beneath northern Lesotho was inflected in late Cretaceous times, but the geotherm given here is significantly displaced to higher temperatures.

TL;DR: In the case of the spinel peridotites, the inclusions are predominantly porphyroclastic-textured spinel Peridotite, although pyroxenites, mafic granulite-facies gneisses and augite megacrysts also occur.

TL;DR: In this article, a thermodynamic model from literature shows that the free energy of the possible parent liquid is higher than that of the two unmixed liquids, although with some doubt, it may have been formed by liquid immiscibility.

TL;DR: In this article, the authors have found relict diopsides in meta-ultrabasic rocks from the Berisal crystalline complex in the Pennine nappe system of the Alps.