安徽东南部二叠系龙潭组砂岩碎屑组分及物源分析  

Sandstone Detrital Composition and Provenance Analysis of the Permian Longtan Formation in Southeastern Anhui Province

作　　者：杜叶龙[1] 李双应[1] 孔为伦[1] 王松[1] 

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009

出　　处：《高校地质学报》2010年第4期509-516,共8页Geological Journal of China Universities

基　　金：安徽省自然科学基金项目(070415205);国家自然科学基金(40972082;40572076)联合资助

摘　　要：砂岩碎屑组分分析是研究盆地沉积物源及其构造演化的重要途径。龙潭组是我国南方重要的含煤层位之一,进一步确定其沉积物来源和源区构造背景具有重要意义。安徽东南部二叠系龙潭组砂岩碎屑组分特征为:单晶石英含量为25%～40%,多晶石英含量为30%～65%,而且细砂岩中,石英多具有溶蚀的边缘;长石含量变化较大,在细砂岩中含量在5%～15%之间,在中粗粒砂岩中含量仅为1%左右;岩屑在细砂岩中的含量为15%～25%,在中粗粒砂岩中含量为10%～20%。砂岩物源分析结果显示,龙潭组砂岩来源于再旋回造山带与消减杂岩带的混合蚀源区,结合含近源砾石特征及区域大地构造背景,可推测研究区龙潭组物源区很可能来自华夏板块与扬子板块碰撞的接壤地带——江南造山带。Detrital composition analysis of sandstone is mainly used to study the provenance of sediments and the tectonic background evolution.The Longtan Formation is one of the major coal-bearing strata in South China.The characteristics of sandstone detrital compositions of the Permian Longtan Formation in southeastern Anhui province show that the contents of monocrystal quart is mostly 25%-40%,and the polycrystal quart 30%-65%.The quart in the fine-grained sandstone usually has a corroded rim.The contents of feldspar show a great variation,mainly 5%-15%in the fine-grained sandstone and about 1%in the medium-to coarse-grained sandstone;Lithic fragments are mainly 15%-25%in the fine-grained sandstone and 10%-20%in the medium-to coarse-grained sandstone.The sandstone detrital compositions and provenance analysis indicate that the sandstone of the Longtan Formation was derived from the mixed sources of recycled orogen and subduction complex.Combining with the gravel characteristics and the regional tectonic setting,it can be inferred that the sources of the Longtan Formation in the study area were mostly derived from the collision zone between the Cathaysia Plate and the Yangtze plate,namely the Jiangnan orogen.

关 键 词：二叠纪 龙潭组砂岩组分 物源分析 安徽东南部 

分 类 号：P534.46[天文地球—古生物学与地层学]