Sedimentary characteristics and environments of the Cretaceous deposits from the Laozhu Basin,Lishui,Zhejiang

The Cretaceous deposits from the Laozhu Basin,Lishui,Zhejiang are redivided on the basis of field outcrops and previous data,and may be grouped into fluvial,lake,volcanic eruption and alluvial fan facies.The Laozhu Basin once went through three phases of deposition-eruption cycles in the extensional settings during the Early Cretaceous,followed by the Zhejiang-Fujian movement during the middle to late Early Cretaceous.This movement gave rise to the relative uplifting of northwestern Zhejiang and anisostatic subsidence of southeastern Zhgejiang.The palaeoclimates graded from the warm and dry conditions during the early stage into xerothermic conditions during the late stage.Till the Late Cretaceous,the Laozhu Basin witnessed compression-and uplift-dominated tectonic settings.