Late Mesozoic crust-mantle interaction and lower crust components in South China

a geochemical study of mafic granulite xenoliths from Cenozoic basalts

Jinhai Yu*, Xisheng Xu, Xinmin Zhou

*Corresponding author for this work

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Mafic granulite xenoliths collected from Cenozoic basalts in SE China can be classified as magmatic granulite and cumulate granulite. Magmatic granulites are characterized by highly concentrated Al2O3, K2O, P2O5, Ba, Sr, Pb, and REE, and low contents of Nb, Zr, Hf and Th, and have an incompatible element abundance pattern similar to that of continental arc basalts. Cumulate granulites are depleted in K2O, P2O5, Rb, Cs and Ba. These granulite xenoliths were the products of crystallization and recrystallization of the basaltic magma underplating into crust-mantle boundary in Late Mesozoic. Sr and Nd isotopic compositions and variation trend of these mafic rocks are the result of crust-mantle mixing and controlled by assimilation and fractional crystallization process (AFC). However, trace element and major element variations were mainly controlled by fractional crystallization. The granulites are similar in geochemistry to surface Late Mesozoic gabbro and basalt in the study area, suggesting a close petrogenetic link between them. Late Mesozoic basaltic magma activities are the most important cause for the formation of extensive contemporaneous granite and rhyolite in the study area. This study and previous data indicate that the lower crust beneath South China is composed of a variety of Paleo- to Meso-proterozoic metamorphic rocks and Late Mesozoic mafic granulites.

Original languageEnglish
Pages (from-to)447-460
Number of pages14
JournalScience in China, Series D: Earth Sciences
Volume46
Issue number5
DOIs
Publication statusPublished - May 2003
Externally publishedYes

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Keywords

  • AFC process
  • Granulite xenoliths
  • Late Mesozoic
  • Lower crust component
  • South China

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