Late Mesozoic interaction between crust and mantle in coastal area of Zhejiang-Fujian

• 作 者: 周金城 陈荣
• 机 构: Department of Earth Sciences, State Key Laboratory of Mineral Deposit Research, Nanjing University,
• 出 处: Progress in Natural Science
• 发表日期: 2000年09期
• 关键词: mantle crust Mesozoic Fujian subduction geochemical coastal magma isotopic conti

This paper summarizes the lithogeochemical features of composite lavas, dikes and plutons composed of early Cretaceous associated basic-acidic igneous rocks from the coastal area of Zhejiang-Fujian. On the basis of the studies on Nd, Sr, Pb isotopic signatures and geochemical characteristics of large ion lithophile elements (LILE), light rare earth elements (LREE) and high field strong elements (HFSE) of these contemporary basic-acidic igneous rocks, it is considered that the source enrichment caused by the subduction of Pacific plate and contamination of crustal rocks and melts during ascending process may lead to the formation of basaltic magmas with a high LILE concentration. These late Mesozoic composite basic-acidic igneous rocks are the products of the interactions between crust and mantle in active continental margin.

This paper summarizes the lithogeochemical features of composite lavas, dikes and plutons composed of early Cretaceous associated basic-acidic igneous rocks from the coastal area of ​​Zhejiang-Fujian. On the basis of the studies on Nd, Sr, Pb isotopic signatures and geochemical characteristics of large ion lithophile elements (LILE), light rare earth elements (LREE) and high field strong elements (HFSE) of these contemporary basic-acidic igneous rocks, it is considered that the source enrichment caused by the subduction of Pacific plate and contamination of crustal rocks and melts during ascending process may lead to the formation of basaltic magmas with a high LILE concentration. These late Mesozoic composite basic-acidic igneous rocks are the products of the interactions between crust and mantle in active continental margin.