江西修水地区中元古界双桥山群浊流沉积

对江西修水地区双桥山群安乐林组和修水组的岩石组合、沉积构造、浊积岩岩相、垂向演化序列进行了详细论述,识别出两个比较完整的浊积扇,其内部可进一步划分为内扇主水道、次级水道、高阶地;中扇分支水道、分支水道漫滩、外缘垛体;外扇沉积,反映了一个从进积到退积的沉积旋回,揭示了从安乐林组发生海退到修水组发生海侵的总体变化趋势.对修水组底部砂岩和砾岩结构、层序特征、横向变化等的系统研究,显示其具有明显的深水重力流特征,系海平面快速下降过程中形成的浊积扇内扇主水道砾岩.研究表明安乐林组与修水组为连续沉积,"修水运动"不存在.

TURBITIDY CURRENT SEDIMENTS OF SHUANGQIAOSHAN GR-OUP IN MIDDLE PROTEROZOIC IN XIUSHUI AREA,JIANGXI PROVINCE

This paper has discussed in detail the rock association, sedimentary tectonic and turbidite petrofacies and vertical evolutionary succession of Anlelin Formation and Xiushui Formation and identified two more complete turbidite fans. The inter part of turbidite fan can be further divided into main channel, secondary channel and high-terrace of inter fan branching channel, flood land between channel and allogenic lobe of middle fan, and outer fan. It reflects a sedimentary cycle from progradation to retrogradation and reveals the changing trendency from regression of Anlelin Formation to progression of Xiushui Formation.The systematic study of the structure, sequence and lateral variation of sandstone and conglomerate in the First Member of Xiushui Formation varifies the characteristics of deep-water gravity current in the member,which can be regarded as main channel conglomerate of inter fan formed during the rapid descent of sea level. Anlelin Formation and Xiushui Formation are continous sediments, and hence "Xiushui Movement" is believed to have not been in existence.