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闽西南大田县境内汤泉花岗闪长岩体呈NE向展布,出露面积约130 km~2,以往被认为是早白垩世岩浆作用的产物。本次研究获得的单颗粒锆石U-Pb年龄为186.8 Ma和179.0 Ma,Rb-Sr等时线年龄为162.02±4.5 Ma,花岗闪长岩中黑云母~(40)Ar/~(39)Ar坪谱年龄为158.1±0.7 Ma,首次确定该岩体应形成于早侏罗世。岩体形成早期(183～162 Ma)处于相对挤压构造环境,冷却速率缓慢(4.76℃/Ma),晚期(162～158 Ma)是在伸展拉张构造环境下较快速冷却(50℃/
The Tangquan granodiorite body in the county of Mintian in southwestern Fujian shows NE-trending distribution with an area of about 130 km ~ 2. It was previously thought to be a product of the Early Cretaceous magmatism. The single zircon U-Pb dating of this study was 186.8 Ma and 179.0 Ma, and the Rb-Sr isochron age was 162.02 ± 4.5 Ma. The biotite-40Ar / 39 ) Ar plateau is 158.1 ± 0.7 Ma and it was first determined that the rock mass should be formed in the Early Jurassic. In the early stage of rock mass formation (183 ~ 162 Ma), the compressive tectonic setting was relatively slow, with a slow cooling rate (4.76 ℃ / Ma) and a late cooling rate (162 ~ 158 Ma)