| 北秦岭构造属性与元古代构造演化 |
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| 关键词:isotopic age magmatic movement tectonics Precambrian Qinling |
| 基金项目:国家自然科学基金项目(编号:40003003)，教育部骨干教师资助计划项目资助。 |
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| Proterozoic Tectonics and Evolutionary History of the North Qinling Terrane |
| Evidence from Precambrian geology, geochemistry and isotopic ages suggests that North Qinling Terrane (NQT) is quite different from North China Block (NCB). The NQT is characterized by distinct higher initial ε Nd (t) values and Pb isotopic ratios, in contrast to the lower initial ε Nd (t)values and Pb isotopic ratios of the NCB. Geological evidence indicates that NQT is also different from South China Block (SCB), especially in Precambrian tectonic and evolution history. Based on synthesized studies of geology and geochemistry, it is suggested that NQT is an independent terrane, whose foundation is an oceanic island formed to the south of the NCB at about 2 000 Ma. The mechanism of two main crust growth events of NQT is vertical accretion and lateral accretion which occurred in 2 200～1 800 Ma and 1 400～900 Ma, respectively. Much evidence indicates that NQT was drifted in an early Proterozoic ocean and connected with the southern margin of NCB at about 1 600 Ma, and then drifted away from NCB due to the overspreading and formation of Kuanping rift-oceanic basin in about 1 300～1 000 Ma. At about 1 000 Ma, the NQT collided with the NCB along the northern boundary fault of Kuanping Group. |
| DONG Yun-peng,ZHANG Guo-wei,ZHU Bing-quan.2003.Proterozoic Tectonics and Evolutionary History of the North Qinling Terrane[J].Acta Geoscientica Sinica,24(1):3-10. |
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