对溧水盆地中生代火山岩系地层划分和时代归属的意见

Some new views on the division and ages of Mesozoic volcanic strata in Lishui Basin

前人工作概述溧水盆地是长江中下游断裂拗陷带中许多继承性火山岩盆地之一,中生代陆相火山岩系广泛分布,其出露面积约占全部出露地层的一半左右,在本区地质发展史上占有重要的地位;它们与本区锶、铁、铜、金及膨润土等矿产的形成也有十分密切的关系。

Based on the synthetic analysis of present data,the petrological study,and Rb-Sr age determina- tions,some new views on the division of Mesozoic volcanic cycles and the equivalent strata are proposed in the paper.Four stratigraphic units,which represent the products of the four volcanic cycles,are named as the Longwangshan,Dawangshan,Guanshan and Jiashan Formations,and geochronologically these four For- mations belong to the Late Jurassic,Early Cretaceous,early Early Cretaceous and Late Cretaceous Epochs re- spectively.