地质论评2011，Vol.57Issue(3)：327-336,10.
浙江沐尘石英二长岩及其镁铁质包体的锆石U-Pb年龄和Hf同位素组成——对岩浆混合作用的示踪
Zircon U-Pb Age and Hf Isotopic Compositions of Quartz Monzonite and Enclosed Mafic Enclaves in Muchen Pluton, Zhejiang Province: Tracing Magma Mixing in Their Petrogenesis
摘要
Abstract
Numerous mafic microgranular enclaves (MMEs) with different shapes are found in quartz monzonites of the Muchen pluton in Zhejiang Province. Precise LA-ICP-MS U-Ph dating was conducted on zircon grains extracted from the host quartz monzonites and the MMEs, yielding crystallization ages of 112.1±1. OMa and 112.4±1.2Ma, respectively. The consistent ages within analytical errors suggest that the host rocks and MMEs were coeval, providing crucial evidence for magma mixing during their petrogenesis. The MMEs commonly show plastic forms and contain similar K-feldspar megacrysts to the host rocks. Furthermore, plagioclases with core-rim zoning texture and apatites with euhedral acicular shape occur widely in the MMEs. These micrographic features are also consistent with the involvement of magma mixing in their petrogenesis. The MMEs and host quartz monzonites show similar zircon Hf isotopic signatures with εHf (t) values ranging from negative to positive. Integrated geological and geochemical characteristics suggest that the MMEs in Muchen pluton were most likely produced by magma mixing between mafic magmas derived from a depleted mantle source and induced felsic magmas generated from partial melting of crust materials.关键词
镁铁质微粒包体/石英二长岩/锆石U-Pb年龄/Hf同位素组成/岩浆混合作用/浙江沐尘岩体Key words
mafic microgranular enclaves/ quartz monzonite/ zircon U-Ph age/ Hf isotopic compositions/ magma mixing/ the Mucheng pluton, Zhejiang province引用本文复制引用
刘亮,邱检生,李真..浙江沐尘石英二长岩及其镁铁质包体的锆石U-Pb年龄和Hf同位素组成——对岩浆混合作用的示踪[J].地质论评,2011,57(3):327-336,10.基金项目
本文为国家自然科学基金资助重点项目(编号40730313)的成果. （编号40730313）
