Abstract
Lamprophyric dikes, mainly of camptonite/monchiquite affinities occur in the Wiedemanns Fjord area. One example contains a complex assemblage of olivine-orthopyroxene-chrome spinel nodules, megacrysts of kaersutite, diopside, strongly reverse-zoned green salite and various spinel phases. Microprobe analyses are presented for all these phases and for the lilac-coloured titansalites and strongly-coloured kaersutites of the groundmass. It is concluded that these minerals record evolution under various P, T and oxidation regimes during the formation of a lamprophyric parent magma. The nodules provide evidence for deep fractures in this area supposedly associated with early rifting in the North Atlantic.
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Brooks, C.K., Rucklidge, J.C. A tertiary lamprophyre dike with high pressure xenoliths and megacrysts from Wiedemanns Fjord, East Greenland. Contr. Mineral. and Petrol. 42, 197–212 (1973). https://doi.org/10.1007/BF00371585
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DOI: https://doi.org/10.1007/BF00371585