University of Tasmania
Browse

File(s) under permanent embargo

Pyroxenites from mantle section of Voykar Ophiolite – melt/peridotite reaction and crystallization in SSZ mantle

journal contribution
posted on 2023-05-21, 03:32 authored by Ivan BelousovIvan Belousov, Batanova, V, Sobolev, A, Savelieva, G, Leonid Danyushevsky, Draayers, E
Pyroxenites from Voykar Ophiolite mantle section provide a great record of processes happening during final stages of evolution of an ophiolite. They are represented by the complete range from clino- to ortho-pyroxenites with websterites and complex dunite-pyroxenite veins also present. Their formation is attributed to various degrees of fractional crystallization and reaction of melts and possibly fluids with host harzburgites during changing P and T conditions. Most of pyroxenite parental melts were migrating through that part of the mantle section from a more depleted and higher temperature harzburgites. Presence of subduction signature is evident from mineral and whole rock compositions. Parental melt with boninite-like trace element patterns is proposed with most likely positioning in lithospheric part of forearc mantle. Orthopyroxenites formed on earliest stages from parental melt/fluid most depleted in REE and highest in silica. As the melt reacted with residual peridotites Si content was decreasing and websterites and clinopyroxenites started to form with increase of Cpx/Opx ratio with decreasing temperature. Olivine websterites and clinopyroxenites formed from the melt saturated in olivine and therefore not reacting with residual peridotites. Formation of pyroxenites triggered minor melting of surrounding harzburgites and some of thin cm sized pyroxenites represent accumulations of such melts.

History

Publication title

Lithos

Volume

388-389

Article number

106063

Number

106063

ISSN

0024-4937

Department/School

School of Natural Sciences

Publisher

Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Rights statement

Copyright 2021 Elsevier

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the earth sciences

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC