Alkali content of alpine ultramafic rocks

Hamilton, Warren; Mountjoy, Wayne

doi:10.1016/0016-7037(65)90062-1

Cited by 21 publications

(1 citation statement)

References 29 publications

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“…The harzburgites are therefore thought to represent depleted upper mantle produced by the partial melting of aluminous upper mantle peridotite and subsequent removal of the basaltic liquid (Hamilton & Mountjoy 1965;Menzies & Allen 1974). The further extraction of much basaltic liquid would seem impossible from the low abundance of elements that are liquid accumulative, and from the highly magnesian nature of the harzburgite mineral phases.…”

Section: Discussionmentioning

confidence: 99%

Magma generation in the upper mantle, field evidence from ophiolite suites, and application to the generation of oceanic lithosphere

Malpas

1978

Phil. Trans. R. Soc. Lond. A

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The Bay of Islands ophiolite may be divided into a lower series of ultramafic tectonites representing mantle material and a higher series of cumulate and extrusive rocks and sediments which may be correlated with oceanic crust. The tectonite series consists of a lower spinel—lherzolite member overlain by harzburgites. Both are cut by numerous olivine-pyroxene veins which represent early crystallization products from a picritic tholeiite magma derived at 18-22 kbar by approximately 23 % partial melting of the spinel lherzolite. The remainder of this magma crystallized as differentiated cumulate and extrusive rocks under crustal conditions. The petrogenetic model derived implies a rising diapiric body beneath an accreting centre and allows for the production of tholeiitic, transitional and mildly alkaline basalts from a single parent. The nature of the basalt erupted depends upon the rate of upwelling and crystallization in the diapir. The model suggests that crystallization takes place in the diapir at depths of less than 60 km.

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Section: Discussionmentioning

confidence: 99%