Abstract Peridotite–magma interaction is important in establishing magma pathways through the mantle and metasomatism of lithospheric mantle. Reactions that consume orthopyroxene produce olivine clinopyroxene are particular interest because these reactions should lead to a redistribution trace elements between solid melt phases at equilibrium. This study examines silica-undersaturated alkaline ...

introduction geological background ophiolites have played a major role in our understanding of earth’s processes ranging from seafloor spreading, melt evolution and magma transport in oceanic spreading centers, and hydrothermal alteration and mineralization of oceanic crust to collision tectonics, mountain building processes, and orogeny. they provide the essential structural, petrological, geo...

Volcanic deposits from the lake Nyos contain ultramafic xenoliths: lherzolites, harzburgites and wehrlites, sometimes containing amphiboles phlogopites. The lithospheric mantle beneath Nyos, as inferred chemical diagrams, has experienced partial melting variably cryptic modal metasomatism of two groups samples that have been distinguished: Group 1 are characterized by spoon-shaped REE patterns,...

Abstract The Eagle’s Nest Ni-Cu-(platinum group element; PGE) deposit occurs within the 2.73 Ga Esker intrusive complex of Ring Fire suite in McFaulds Lake greenstone belt northern Ontario. Mineralization along margin a formerly ~500-m-high, ~85-m-thick, >1,500-m-long subvertical structurally rotated blade-shaped dike composed harzburgite, lherzolite, and wehrlite. Three sulfide textural...

Alaskan-type complexes in British Columbia are potentially important hosts for economic concentrations of platinum-group elements (PGEs: Ruhlee, 1986; Evenchick er al.. IYXh) as well as other commodities such as chrome, nickel, cobalt, gold. jade and asbestos. To date, only the platinum-rich placers of the Tulameen complex have been exploited economically, yielding some 680 000 grams of impure ...

introduction worldwide, ni-cu and pge magmatic sulfide deposits are confined to the lower parts of stratiform mafic and ultramafic complexes. however, ophiolite mafic and ultramafic complexes have been rarely explored for sulfide deposits despite the fact that they have been extensively explored and exploited for chromite. sulfide saturation during magmatic evolution is necessary for sulfide mi...

This paper presents results of modelling reaction between peridotite and fractionating tholeiitic basalt in simple and complex silicate systems. Reactions are outlined in appropriate binary and ternary silicate systems. In these simple systems, the result of reactions between 'basalt' and 'peridotite' may be treated as a combination of Fe-Mg exchange and mass transfer reactions at constant Fe/M...

New geochronological data and published structural and stratigraphic data show that two distinctly different ophiolitic assemblages formed in general proximity to one another at nearly the same time and were subsequently imbricated along a regional thrust zone. The Josephine ophiolite constitutes a complete oceanic crust and upper mantle sequence which lies within the western Jurassic belt of t...

Abstract The reliability of eight Fe–Mg exchange geothermobarometers for garnet-bearing peridotites, pyroxenites and eclogites has been examined using a database comprised more than 300 published peridotite, pyroxenite eclogite experiments conducted from 10 to 70 kbar 850 &gt; 1650 $$^\circ{\rm C}$$ <mm...