论文部分内容阅读
There are three types of zircon (i.e. Zircon A, Zircon B and Zircon C) in the microgranitoid enclaves from the Qingtian granite. Zircon A is of the smallest I_(pr), I_(py) and I_(el) values with the largest range of variations; Zircon C is of the largest I_(pr), I_(py) and I_(el) values with the smallest range of variations; and Zircon B is intermediate among the three types. The microprobe analysis of zircon demonstrates that the contents of trace elements (Hf, U, Y, Th) increase progressively with larger and larger variation from Zircon A through Zircon B to Zircon C. These characters snggest that the three types of zircon in the enclaves may have formed successively during the cooling process of enclave magma, corresponding to different sites along with the intrusion of enclave magma. Because of positive correlations of the UO_2/HfO_2 ratio with I_(pr), the ThO_2/Y_2O_3 ratio with I_(py), and the UO_2/(ThO_2 + Y_2O_3) ratio with I_(el), it is suggested that the variation in zircon typology is caused
There are three types of zircon (ie Zircon A, Zircon B and Zircon C) in the microgranitoid enclaves from the Qingtian granite. Zircon A is the smallest I_ (pr), I_ (py) and I_ (el) values with the largest range of variations; Zircon C is the largest I_ (pr), I_ (py) and I_ (el) values with the smallest range of variations; and Zircon B is intermediate among the three types. The microprobe analysis of zircon demonstrates that the contents of trace elements (Hf, U, Y, Th) increase progressively with larger and larger variation from Zircon A through Zircon B to Zircon C. These characters snggest that the three types of zircon in the enclaves may have formed successively during the cooling process of enclave magma, corresponding to different sites along with the intrusion of enclave magma. Because of positive correlations of the UO_2 / HfO_2 ratio with I_ (pr), the ThO_2 / Y_2O_3 ratio with I_ (py), and the UO_2 / (ThO_2 + Y_2O_3) ratio with I_ (el), it is suggested that the variation in zircon t ypology is caused