International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

Fluid induced melting in mantle xenoliths and some implications for the continental lithospheric mantle from the Minusinsk Region (Khakasia, southern Siberia)

Published: Jun 2007

Pages: 211 - 228

Authors: ISTVAN KOVACS, KAROLY HIDAS, JORG HERMANN, VICTOR SHARYGIN, CSABA SZABÓ, THEODOROS NTAFLOS

Abstract: Eleven representative xenoliths from the Minusinsk Region, southern Russia were studied in order to highlight the characteristic features of the subcontinental lithospheric mantle beneath the region. Type-I xenoliths show that the lithosphere underwent various degree of depletion overprinted by enrichment processes leading to LREE-enriched pyroxenes. Estimated equilibrium temperature for the xenoliths is in the range of 960–1050 ºC. Type-II xenoliths are the result of crystallization from a possibly basaltic melt close to the crust-mantle boundary. Three xenoliths in the Type-I series show evidence of incipient melting such as spongy rims of pyroxenes and interstitial glass. The spongy rims of clinopyroxene consist of clinopyroxene and glass with modal proportion of approximately 82 and 18 %, respectively. Orthopyroxene rim contains olivine (65 %) and glass (35 %) with subordinate amounts of clinopyroxene (

Keywords: Minusinsk Region, lithospheric mantle, petrology, major and trace element geochemistry, melting in the upper mantle

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