Journal article

Thermal state and composition of the lithospheric mantle beneath the Daldyn kimberlite field, Yakutia

WL Griffin, FV Kaminsky, CG Ryan, SY OReilly, TT Win, IP Ilupin

TECTONOPHYSICS | ELSEVIER SCIENCE BV | Published : 1996

Abstract

The proton microprobe has been used to study the distribution of trace elements in garnet and chromite concentrates from the Udachnaya kimberlite and three smaller, low-grade kimberlites from the Daldyn kimberlite field. Garnet thermobarometry and classical P-T estimates for megacrystalline peridotite xenoliths both suggest a Paleozoic geotherm beneath the Daldyn area that is close to a 35 mW/m2 conductive model. Finer-grained xenoliths with T 190 km. High-T Iherzolite garnets carry a distinctive trace-element fingerprint showing enrichment in Zr, Ti, Y and Ga, interpreted as due to the infiltration of asthenosphere-derived melts. This melt-related metasomatic signature becomes the dominant..

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University of Melbourne Researchers