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Late Devonian Diamondiferous Kimberlite and Alkaline Picrite (Proto-kimberlite?) Magmatism in the Arkhangelsk Region, NW Russia 总被引:7,自引:4,他引:3
MAHOTKIN I. L.; GIBSON S. A.; THOMPSON R. N.; ZHURAVLEV D. Z.; ZHERDEV P. U. 《Journal of Petrology》2000,41(2):201-227
Widespread penecontemporaneous igneous activity affected NWRussia (the Kola Peninsula and adjoining areas to the SE aroundArkhangelsk) during the Late Devonian (360380 Ma). Magmatismvaries from tholeiitic basalts, erupted in the axial regionsof former Middle Proterozoic (Riphean) rifts, to strongly alkalinerock-types on and marginal to Archaean cratons. NNE of Arkhangelskkimberlites, olivine lamproites and alkaline picrites were emplaced;all these rock-types are diamondiferous to varying extents.Higher TiO2 (and also total Fe) distinguish predominantly mica-poorEastern Group kimberlites (TiO2 = 2·43·1wt %) and spatially associated alkaline picrites (TiO2 = 3·23·7wt %) from nearby micaceous Western Group kimberlites (TiO2= 0·81·1 wt %). Each rock-type also hasdistinctive rare earth element (REE) patterns, and 相似文献
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