Hf isotopic compositions and geological significance; a case study of Mesozoic batholiths and mafic enclaves in North Taihang

作者：Chen Z C^*; Chen B; Tian W

来源：Acta Petrologica Sinica, 2007, 23(2): 295-306.

• zircon Hf isotopic analysis
• mafic enclaves
• Mesozoic magmatism
• Taihang Mountains

Extensive Mesozoic magmatic rocks were emplaced in the northern part of the Taihang Mountains, which are dominated by intermediate la felsic rocks with minor but widespread mafic microgranular enclaves, accompanied by subordinate mafic bodies. Zircon SHRIMP U-Pb dating yields a weighted mean Pb-206/U-238 age of ca. 126Ma for the injection of mafic enclaves, which is identical to the emplacement age of their host rocks. LA-MC-ICPMS in-situ Hf isotopic analysis of zircons suggests that the mafic rocks basically originated from partial melting, of an enriched mantle, contaminated by crustal components en route to crustal levels, whereas the dominant intermediate to felsic batholithes formed from a mixing/mingling process between enriched mantle-derived mafic magma and crustal-derived granitic magma. The mafic macrogranular enclaves in the batholith represent mafic magma that were injected into felsic magma chamber followed by interaction with the latter.

• 出版日期2007-2
• 单位北京大学