赣西北地区中元古界双桥山群沉积学特征

Sedimentary features of the Mesoproterozoic Shuangqiaoshan Group in northwe stern Jiangxi

综合1∶5万区调成果,系统阐述了赣西北地区双桥山群的沉积学特征,认为是一套形成于滨海-半深海环境的重力流沉积体系,其中发育一系列重力流沉积相单元,即块状混杂砾岩相、正递变砾岩相、经典浊积岩相等。对各单元基本层序特征进行了总结论述,并结合地球化学特征及粒度分析成果探讨了沉积环境。

By integrating the achievements scored during the1∶50000 re gional geological survey,this paper systematically elucidates the sedimentology features of the Shuangqiaoshan Group in northwestern Jiangxi.This group is a gravity flow sedimentary system formed in a littoral-bathyal environment ,in w hich there are a number of gravity flow sedimentary facies units,such as massi ve hybrid conglomerate facies,normal grading conglomerate facies and classical turbidite facies.In this paper the basic sequence features of these units are summarized and discussed,and on that basis,combined with the geochemical featu res and grain-size analysis,the sedimentary environment is preliminarily disc ussed.