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Primitive olivine melanephelinite dykes from the Orkney Islands, Scotland

  • B. G. J. Upton (a1), R. H. Mitchell (a2), A. Longs (a3) and P. Aspen (a1)

Abstract

Two suites of Permian dykes in the Orkney Islands consist of a predominantly ENE trending camptonite suite and a mainly N-to NE-trending suite formerly referred to as monchiquitic. Some of the silica-poor and more magnesium dykes in the latter suite can be more precisely defined as olivine melanephelinites. Within the parochial context of the British Isles, such compositions appear to be unique. The magmas are deduced to have been primitive, small-scale (? < 0.2%) partial melt products of the asthenospheric mantle that have experienced relatively little modification in transit through the lithosphere.

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Primitive olivine melanephelinite dykes from the Orkney Islands, Scotland

  • B. G. J. Upton (a1), R. H. Mitchell (a2), A. Longs (a3) and P. Aspen (a1)

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