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溧水火山岩盆地是长江中下游地区众多中生代火山岩盆地之一,在盆地内自下而上发育有龙王山组、大王山组、姚家边组和甲山组粗面质火山岩和若干个同源的次火山侵入岩体。针对溧水盆地火山岩-次火山岩进行系统的锆石U-Pb年代学研究,结果显示,龙王山组玄武质粗面岩的锆石U-Pb年龄为135 Ma±1 Ma,大王山组粗安岩的锆石U-Pb年龄为131 Ma±1 Ma,姚家边组粗安岩的锆石U-Pb年龄为128 Ma±1 Ma,另外1个粗安斑岩体的年龄为131 Ma±1 Ma,它们均为早白垩纪岩浆活动的产物。上述年龄数据与长江中下游地区其他盆地火山岩的年龄基本一致,表明长江中下游地区中生代火山岩的喷发时代主要集中在135Ma~127Ma之间,均受制于中国东部岩石圈减薄的伸展构造背景。
Lishui volcanic basin is one of a large number of Mesozoic volcanic basins in the middle and lower reaches of the Yangtze River. In the basin, the Lower Wangshan Formation, the Dawangshan Formation, the Yaojibian Formation and the Jiashan Formation are formed from bottom to top in the basin. Volcano intrusion rock. A systematic zircon U-Pb dating of volcanic-subvolcanic rocks in Lishui Basin shows that the zircon U-Pb age of the Longwangshan formation is 135 Ma ± 1 Ma and that of the Dawangshan Formation Zircon U-Pb ages of 131 Ma ± 1 Ma. The U-Pb zircon ages of the Yaojiabian formation are 128 Ma ± 1 Ma and the age of the other one is 131 Ma ± 1 Ma, all of which were the product of early Cretaceous magmatism. The age data above are consistent with the volcanic ages of other basins in the middle and lower reaches of the Yangtze River, indicating that the Mesozoic volcanic eruptions occurred in the middle and lower reaches of the Yangtze River mainly between 135 Ma and 127 Ma, both of which are controlled by the lithospheric thinning extensional tectonic setting in eastern China.