The Sytykanskaya kimberlite pipe:Evidence from deep-seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit,Yakutia,Russia

作     者：I.V.Ashchepkov A.M.Logvinova L.F.Reimers T.Ntaflos Z.V.Spetsius N.V.Vladykin H.Downes D.S.Yudin A.V.Travin L.V.Makovchuk V.S.Palesskiy O.S.Khmel'nikova 

作者机构：Institute of Geology and Mineralogy SB RAS Vienna University Alrosa Stock Company Institute of Geochemistry SB RAS Birkbeck CollegeUniversity of LondonUKMalet Street 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2015年第6卷第5期

页      面：687-714页

核心收录：

学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学] 

基　　金：supported by RBRF grants 05-05-64718,03-05-64146,08-05-00524,11-05-00060,11-05-91060-PICS jointresearch projects of IGM SB RAS and ALROSA Stock Company 77-2,65-03,02-05,grant of the President of Russia MK-3240.2014.5 

主　　题：Kimberlites Mantle lithosphere Mantle xenoliths Th 

摘      要：Mantle xenoliths（150） and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field（Yakutia） were analyzed by EPMA and LAM ICP *** P-TX-f（O2） diagrams minerals from xenoliths show widest variations,the trends P-Fe#-CaO,f（O2）for minerals from porphyric kimberlites are more stepped than for xenocrysts from *** PTX points mark moving for protokimberlites from the lithosphere base（7.5 GPa） to pyroxenite lens（5-3.5 GPa） accompanied by Cr increase by AFC and creation of two trends P-Fe#OI10-12%and13-15%.The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 C near Moho was *** oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere *** inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated *** for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider *** reveal S-shaped REE *** clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC *** for garnets display less inclined patterns and Ba-Sr troughs but enrichment in ***40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic（1154 Ma） age of metasomatism in early Rodinia *** glimmerites with richterite- like amphiboles mark1015 Ma plume event in Rodinia ***600-550 Ma stage manifests final Rodinia *** last 385 Ma metasomatism is protokimberlite-related.