^(40)Ar/^(39)Ar geochronological constraints on syn-orogenic strike-slip movement of Tan-Lu fault zone  

作　　者：ZHUGuang LIUGuosheng W.J.Dunlap C.Teyssier WANGYongsheng NIUManlan 

机构地区：[1]SchoolofResourceandEnvironmentEngineering,HefeiUniversityofTechnology,Hefei230009,China [2]ResearchSchoolofEarthSciences,AustralianNationalUniversity.ActonACT0200,Australia [3]DepartmentofGeologyandGeophysics,UniversityofMinnesota,MinneapolisMN55455,USA

出　　处：《Chinese Science Bulletin》2004年第5期499-508,共10页

摘　　要：Two phases of sinistral strike-slip ductile shear belts occur on the eastern margin of the Dabie orogenic belt. A muscovite ^40Ar/^39Ar plateau age of 128 Ma was obtained from mylonite in the later ductile shear zone. Three muscovite samples separated from mylonites of 3 localities in the earlier ductile shear belts yield ^40Ar/^39Ar plateau ages of 192.5±0.7 Ma, 189.7±0.6 Ma and 188.7±0.7 Ma, respectively. They are interpreted as cooling ages of the earlier sinistral strike-slip deformation. It is suggested that left-lateral displacement of the Tan-Lu fault zone started in a late stage of the collision orogeny in the Dabie-Sulu orogenic belt between the North and South China plates. Therefore, the earlier Tan-Lu fault zone was syn-orogenic strike-slip tectonics. The fault zone was used again for sinistral displacement during tectonic activities of peri-Pacific regime in Early Cretaceous. It is proposed that the fault zone occurred as a transform fault during the orogenic process.Two phases of sinistral strike-slip ductile shear belts occur on the eastern margin of the Dabie orogenic belt. A muscovite 40Ar/39Ar plateau age of 128 Ma was obtained from mylonite in the later ductile shear zone. Three muscovite samples separated from mylonites of 3 localities in the earlier ductile shear belts yield 40Ar/39Ar plateau ages of 192.5 ±0.7 Ma, 189.7 ±0.6 Ma and 188.7 ±0.7 Ma, respectively. They are interpreted as cooling ages of the earlier sinistral strike-slip deformation. It is suggested that left-lateral displacement of the Tan-Lu fault zone started in a late stage of the collision orogeny in the Dabie-Sulu orogenic belt between the North and South China plates. Therefore, the earlier Tan-Lu fault zone was syn-orogenic strike-slip tectonics. The fault zone was used again for sinistral displacement during tectonic activities of peri-Pacific regime in Early Cretaceous. It is proposed that the fault zone occurred as a transform fault during the orogenic process.

关 键 词：氩 地质年代学 走向滑距运动 断层带 

分 类 号：P542.3[天文地球—构造地质学] P597.3[天文地球—地质学]