浙江丽水老竹盆地白垩系沉积特征及沉积环境

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

关键词:  浙江  老竹盆地  白垩纪  沉积特征  沉积环境

Key words:  Zhejiang  Laozhu Basin  Cretaceous  sedimentary characteristics  sedimentary environment

摘要:

在野外露头观察和对前人研究成果整理的基础上,对浙江丽水老竹盆地白垩纪地层进行了对比和重新划分,并进行了相带划分,识别出河流、湖泊、火山喷发及冲积扇相。老竹盆地在早白垩世经历了三次拉张背景下的断陷盆地沉积-喷发旋回;早白垩中晚期的浙闽运动导致浙西北主体的相对上升、接受剥蚀和浙东南的不均衡沉降,气候由早期的温暖干旱变为晚期的干热环境;至晚白垩世,老竹盆地整体由拉张断陷为主向挤压、隆升为主的构造背景转化。

Abstract:

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.