摘要
应用锆石SHRIMP定年方法对云蒙山片麻状花岗岩进行年代学研究 ,得到 4组年龄 :14 4± 4Ma、16 0～ 16 3Ma、193～ 2 18Ma和 2 4 16Ma。其中 14 4± 4Ma代表了云蒙山岩体的侵位时间 ,16 0～ 16 3Ma和 193～ 2 18Ma两组年龄可能是岩浆侵位过程中捕虏锆石的年龄。 2 4 16Ma与Davis等的锆石U_Pb法上交点年龄 (190 0～ 2 4 0 0Ma)一致 ,可能反映了原岩的时代 ,说明该花岗岩来源于晚太古代片麻岩的局部熔融或者是岩浆侵位过程中捕获了晚太古代的锆石。
Zircon SHRIMP dating was performed to study Yunmengshan gneissic granite and, as a result, four groups of zircon ages were obtained, namely, 144±4 Ma, 160～163 Ma, 193～218 Ma and 2?416 Ma. The age of 144±4 Ma represents the emplacement age of Yunmengshan gneissic granites, and can serve as new important evidence for the emplacement of Yunmengshan gneissic granite. The two age groups of 160～163 Ma and 193～218 Ma probably represent the ages of zircon captured during the emplacement of magma. The age of the inherited zircon is about 2?416 Ma, identical with the zircon U-Pb upper-intercept ages by Davis (1996). This suggests that Yunmengshan gneissic granite was probably derived from partial melting of late Archean gneiss or that late Archean zircon was captured during magmatic intrusion.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2004年第2期141-146,共6页
Acta Petrologica et Mineralogica
基金
中国地质调查局资助项目 ( 2 0 0 113 90 0 0 18)
国家自然科学基金重点资助项目 ( 4 0 2 3 40 48)
