南盘江印支期前陆盆地中上三叠统深水浊积岩沉积特征

SEDIMENTARY CHARACTERISTCS OF THE MIDDLE-UPPER TRIASSIC DEEP-WATER TURBIDITE IN INDOSINIAN NANPANJIANG FOREL FORELAND AND BASIN

南盘江印支期前陆盆地，于中晚三叠世发育了一套厚度较大，分布广泛的陆屑浊积岩。按照沉积结构，构造和岩性特征，可划分出四种浊积岩相类型。其沉积模式为海底扇，并具三个幕次的沉积活动，其物源来自盆地南端，即为印支板块与扬子板块碰撞形成的前陆褶冲带。经研究，百蓬期（Ｔ２１）浊积盆地位于ＣＣＤ面之下，而河口期（Ｔ２２）和法郎期（Ｔ１３）烛积盆地位于ＣＣＤ面之上。

The Middle -Upper Triassic clastic turbidite with a large thickness is widely dispersed over the Indosinian Nanpanjiang foreland basin .According to the sedimentary structure and lithology,the turbidite may be divided into the four types of turbidite facies.The research indicates sedimentary model for the submarine fan with three episodes of activity.The source area was located in the south of the basin,i e,the foreland thrustfold belt resulting from the collision of the indo-China plate with the Yangtze plate. Besides,study of the sedimentary structure and muddy turbidite shows that Beipeng turbidite basin(T 2 1)was beneath the carbonate compensation depth(CCD),while the Hekou(T 2 2)and Falang(T 1 3)turbidite basins were aere CCD.