福建永安喀斯特石林形成年代及发育过程

On the Karst Formation Age and Developing Process of Yong'an,Fujian Stone Forest

根据对永安石林地区地质、水文地质条件的分析,利用不平衡铀系法,对区内不同高程位置的钙华沉积物岩样进行年龄测定,确定了永安石林形成年代在中更新世以来约25万年。并结合永安地区地质构造历史及闽江流域发育演化过程,分析得出永安石林主要是在第四纪以后大湖盆地处于剥蚀环境下,伴随地壳间歇性抬升运动,石炭纪、二叠纪石灰岩上覆岩层逐渐被风化剥蚀后形成的。

Several tufaceous rock samples, collected from different altitude at Yong＇an stone forest, were measured by Uranium-series Disequilibrium method. The results show that Yong＇ an Stone Forest＇s formation age is approximately 250 thousand years since Pleistocene epoch, later than Lunan stone forest. Considering the history of Yong＇an area geologic structure and the evolution process of Mingjiang River Basin, the results also show that the developing process of Yong＇an stone forest. In the process of gradual weathering and erosion of the rock overlying on carboniferous and permian, Yong＇an stone forest is formed accompanied by interval lifting movement of crust, in the background of Minjiang river drainage area formation and Dahu basin under erosion since Quaternary.