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野外调查在景洪曼别和思茅大新山地区大新山组发现放射虫硅质岩、玄武岩地层层序.放射虫动物群包括Follicucullus和Pseudoalbaillella等,地质时代为中二叠世晚期至晚二叠世早期.景洪曼别地区硅质岩SiO2含量均在92％以上,MnO/TiO2平均比值为2.15,Al/（Al+Fe+Mn）比值小于或约等于0.1,Ce/Ce＊平均值为0.4,为远洋型硅质岩;而大新山地区的硅质岩SiO2含量相对较低,MnO/TiO2比值为0.27,Al/（Al+Fe+Mn）比值为0.49,Ce/Ce＊比值为0.88,为大陆边缘型硅质岩.两地玄武岩均为拉斑玄武岩,其主元素、稀土和微量元素均显示洋脊玄武岩特征,说明澜沧江构造带大新山组除包含岛弧火山岩外,还存在洋壳型火山岩和硅质岩,代表了活动大陆边缘沉积组合.
Field investigations revealed the sequence of radiolarian chert and basalt in the Jinghushan Dashatu Formation in Jinghongman, Simao, Laos, which includes Follicucullus and Pseudoalbaillella, and the geological age is Late Late Permian to Late Permian In the early stage, the SiO2 contents of cherts in Jinghongman area were more than 92%, the average ratio of MnO / TiO2 was 2.15, the ratio of Al / (Al + Fe + Mn) was less than or equal to 0.1, and the average Ce / Ce * was 0.4 , And is of oceanic chert; while the SiO2 content of cherts in Daxunshan area is relatively low, with a MnO / TiO2 ratio of 0.27, a Al / (Al + Fe + Mn) ratio of 0.49 and a Ce / Ce * ratio of 0.88. The continental basalts are continental chert basalt, and the main elements, rare earths and trace elements show the characteristics of oceanic basalts, which indicates that besides the arc-bearing volcanic rocks, the Daxuanshan Formation in the Lancangjiang structural belt also contains the oceanic crust Volcanic and chert, representing active continental margin sedimentary assemblages.