Results 71 to 80 of about 7,121 (239)

Petrogenesis of South Armorican serpentinized peridotites [PDF]

Lithos, 2018
Abstract Twenty three serpentinite samples collected from five outcrops in south Brittany (Audierne near Quimper, Champtoceaux near Nantes), western France, were studied using optical microscopy, electron microprobe (EMP), inductively-coupled optical emission spectroscopy (ICP-OES), inductively-coupled plasma mass spectrometry (ICP-MS), and laser ...
Aertgeerts, Geoffrey, Lorand, Jean-Pierre, Monnier, Christophe, La, Carole   +3 more
openaire   +4 more sources

Genesis of primitive Hawaiian rejuvenated-stage lavas: Evidence for carbonatite metasomatism and implications for ancient eclogite source [PDF]

arXiv, 2020
To constrain a contribution of deep carbonated mantle, to fractionation of Hf relative to rare earth elements (REE) in volcanic series, we examine available high-quality data on major, trace element and Nd-Hf isotope compositions of primitive lavas and glasses erupted during preshield, postshield and mostly rejuvenated stage of the Hawaiian hot spot ...
arxiv  

Variable Upper Mantle Geochemical Processes Constrained From Independent Component Analysis of the Fizh Massif, Northern Oman Ophiolite

Geochemistry, Geophysics, Geosystems
We statistically analyzed the whole‐rock compositions of peridotites in the Oman ophiolite using a multivariate statistical technique called independent component analysis (ICA) to better understand the processes within the ophiolitic mantle section that
Yuto Miki, Eiichi Takazawa, Kenta Ueki, Tatsu Kuwatani   +3 more
doaj   +1 more source

New model of chromite and magnesiochromite solubility in silicate melts [PDF]

arXiv, 2020
Chromite is a key magmatic mineral frequently used as petrogenetic indicator of physico-chemical conditions of mafic magma crystallization. In this work, magnesiochromite and chromite solubility in a natural basalt and an iron-free haplobasalt was investigated at 1440{\deg}C and atmospheric pressure under controlled CO-CO2 gas mixtures corresponding to
arxiv  

Origin of Pyroxenite-Peridotite Veined Mantle by Refertilization Reactions: Evidence from the Ronda Peridotite (Southern Spain) [PDF]

Journal of Petrology, 2008
The Ronda orogenic peridotite (southern Spain) contains a variety of pyroxene-rich rocks ranging from high-pressure garnet granulites and pyroxenites to low-pressure plagioclase–spinel websterites. The ‘asthenospherized’ part of the Ronda peridotite contains abundant layered websterites (‘group C’ pyroxenites), without significant deformation, that ...
Bodinier, Jean-Louis, Garrido, C. J., Chanefo, I., Bruguier, Olivier, Gervilla, F.   +4 more
openaire   +5 more sources

Genesis of pyroxenite veins in supra-subduction zone peridotites: Evidence from petrography and mineral composition of Egiingol massif (Northern Mongolia)

China Geology, 2020
: Swarms of orthopyroxenite and websterite veins are found within Egiingol residual SSZ peridotite massif of Dzhida terrain (Central Asian Orogenic Belt, Northern Mongolia).
Anas A. Karimov, Marina A. Gornova, Vasiliy A. Belyaev, Aleksander Ya. Medvedev, Nikolay V. Bryanskiy   +4 more
doaj  

The response of borehole water levels in an ophiolitic, peridotite aquifer to atmospheric, solid Earth, and ocean tides

Journal of Hydrology X, 2023
Peridotite aquifers are ubiquitous on Earth, but most are in the deep-sea, and thus difficult to access. Ophiolites provide a unique opportunity to study peridotite aquifers, and the Oman Drilling Project established a Multi-Borehole Observatory in a ...
R.A. Sohn, J.M. Matter
doaj  

A Model for Melt‐Preferred Orientation and Permeabilities in Deformed Partially Molten Peridotites

Geochemistry, Geophysics, Geosystems
In a deforming partially molten rock, melt concentrates into a grain‐scale melt pocket aligned at a preferred orientation (melt‐preferred orientation, or MPO).
Boda Liu, Chao Qi, Ross N. Mitchell, Cin‐Ty A. Lee, Chuan‐Zhou Liu   +4 more
doaj   +1 more source

COMPOSITIONAL AND THERMAL DIFFERENCES BETWEEN LITHOSPHERIC AND ASTHENOSPHERIC MANTLE AND THEIR INFLUENCE ON CONTINENTAL DELAMINATION

Геодинамика и тектонофизика, 2015
The lower part of lithosphere in collisional orogens may delaminate due to density inversion between the asthenosphere and the cold thickened lithospheric mantle. Generally, standard delamination models have neglected density changes within the crust and
A. I. Kiselev, A. V. Ivanov, B. S. Danilov   +2 more
doaj   +1 more source

Global variations in abyssal peridotite compositions

Lithos, 2016
AbstractAbyssal peridotites are ultramafic rocks collected from mid-ocean ridges that are the residues of adiabatic decompression melting. Their compositions provide information on the degree of melting and melt–rock interaction involved in the formation of oceanic lithosphere, as well as providing constraints on pre-existing mantle heterogeneities ...
openaire   +4 more sources