滇西南澜沧地区南段组砂岩粒度特征与意义  

GRAIN SIZE CHARACTERISTICS AND SIGNIFICANCE OF SANDSTONES OF NANDUAN FORMATION IN LANCANG AREA,SOUTHWESTERN YUNNAN

作　　者：王志忠 王瑞[1] 严城民[2] 徐启胜 刘仕承 周听全 王国辉 WANG Zhi-Zhong;WANG Rui;YAN Cheng-Min;XU Qi-Sheng;LIU Shi-Cheng;Zhou Ting-quan;WANG Guo-Hui(Yunnan Gold Mining Group Co.LTD,Kunming 650200;Regional Geological and Mineral Investigation Brigade,Yunnan Bureau of Geology and Mineral Resources,Yuxi 653100)

机构地区：[1]云南黄金矿业集团股份有限公司,云南昆明650200 [2]云南省地矿局区域地质矿产调查大队,云南玉溪653100

出　　处：《云南地质》2023年第2期138-144,共7页Yunnan Geology

摘　　要：近期完成的1∶50000区域地质调查中,在澜沧地区南段组(DCn)三个岩性段不同类型砂岩中采集了27件粒度分析样品,结果表明:沉积环境分属三角洲、海岸带、大陆斜坡浊流环境,主要为海进层序。三角洲环境砂岩具三角洲上前滨、河流中之边滩、支流河口砂坝特征。海岸带砂岩具三角洲支流河道中之主河道、邻近天然堤浅水支流河道特征。大陆斜坡浊流环境砂岩与浊流沉积中之哈德孙海下扇相似,更好地反映了古特提斯昌宁-孟连盆地形成与演化历史。In the recently completed 1:50000 regional geological survey,27 samples for grain size analysis were collected from different types of sandstones in three lithologic sections of the Nanduan Formation(DCn)in Lancang area.The formation is mainly a Marine entering sequence,and the sedimentary environment is divided into delta,coastal zone and continental slope turbidity current environment.The sandstones in the delta environment have the characteristics of the foreshore of the delta,the point bar,and the Tributary estuary sand bar.The sandstones in the coastal zone have the characteristics of the main channel of the delta tributaries and the shallow tributaries near the natural levees.The characteristics of sandstones in turbid-current environment on continental slope are similar to those of Hudson subfan in turbid-current deposition,which better reflects the formation and evolution history of the Paleo Tethys Chaning-Menglian Basin.

关 键 词：砂岩粒度分析 特征与意义 南段组 澜沧地区 云南普洱 

分 类 号：P588.37[天文地球—岩石学]