Comprehensive refertilization of lithospheric mantle beneath the North China Craton: further Os-Sr-Nd isotopic constraints

LDEO Publication: 
Yes
Publication Type  Journal Article
Year of Publication  2009
Authors  Zhang, H.F.; Goldstein, S.L.; Zhou, X.H.; Sun, M.; Cai, Y.
Journal Title  Journal of the Geological Society
Volume  166
Pages  11
Start Page  249
Journal Date  03/2009
Publisher  GEOLOGICAL SOC PUBL HOUSE, UNIT 7, BRASSMILL ENTERPRISE CENTRE, BRASSMILL LANE, BATH BA1 3JN, AVON, ENGLAND
ISSN Number  0016-7649
Key Words  SPINEL PERIDOTITE XENOLITHS; SINO-KOREAN CRATON; EAST-AFRICAN RIFT; WESTERN SHANDONG PROVINCE; RE-OS; CONTINENTAL-CRUST; SUBCONTINENTAL MANTLE; MESOZOIC BASALTS; MELT PERCOLATION; TECTONIC IMPLICATIONS
Abstract  

Mantle peridotitic xenoliths in Cenozoic basalts from Hannuoba, on the northern margin of the Archaean North China Craton. have variable Re (0.01 0.30 ppb) and Os (2.7 6.2 ppb) abundances and Os-187/Os-188, (0.1138 0.1236) ratios. These xenoliths yield a range of Proterozoic Re depletion ages of 0.8 2.2 Ga that show a general correlation with olivine Fo. Mantle xenoliths in Cenozoic basalts from the centre and southern margin of the North China Craton also overwhelmingly show Proterozoic Re depletion ages that correlate with olivine Fo. These Re ON age features tire completely different from those of Palaeozoic kimberlite-borne peridotitic xenoliths, which hake Archaean ages. I his age distinction between xenoliths associated with Palaeozoic and Cenozoic volcanism indicates that the present-day lithospheric mantle was dominantly not newly accreted during the Phanerozoic but instead was transformed from the ancient lithospheric mantle by interaction with melts. The Re ON data in combination with the geochemical and Sr Nd isotopic features of peridotitic xenoliths from the Cenozoic basalts of the North China Craton demonstrate the presence of multiple stages of mantle metasomatic overprints in the lithospheric mantle. I his study thus further indicates that lithospheric transformation through melt rock interaction could be an important mechanism for compositional refertilization during the Phanerozoic.

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