北羌塘乌兰乌拉湖地区白垩纪岩石地层及沉积环境

Cretaceous lithostratigraphy and sedimentary environment in the Ulan Ul Lake area,northern Qiangtang

详细描述了北羌塘乌兰乌拉湖地区白垩纪地层剖面,将区内白垩系划分为错居日组和桑恰山组。沉积相分析表明,乌兰乌拉湖地区错居日组主要为冲积扇至河流相沉积,岩性及厚度变化较大,而桑恰山组为湖泊、湖三角洲至河流相沉积.初步认为错居日组为早白垩世地层,桑恰山组为早白垩世晚期至晚白垩世地层。

The Cretaceous sections in the Ulan Ul Lake area,northern Qiangtang,are described in details.The Cretaceous in the area is divided into the Cuojuri Formation and Sangqiashan Formation.Sedimentary facies analysis indicates that the Cuojuri Formation in the Ulan Ul Lake area is composed of alluvial to fluvial deposits and highly varied in lithology and thickness and that the Sangqi ashan Formation is composed of lacustrine and lake deltaic to fluvial deposits.It is proposed that the Cuojuri Formation is Early Creta-ceous in age and the Sangqiashan Formation is Early to Late Cretaceous in age.