兰木组标准剖面位于东兰国家地质公园兰木地区，由原广西石油普查大队陆中求等人于1961年命名。岩性为细砂岩、粉砂岩夹泥岩或互层组成复理石、类复理石韵律层；沉积构造复杂，常见各种不完整的鲍马序列、底模构造及流动变形构造；富含菊石、角石及双壳类等生物化石。兰木组的发现为解译桂西北地区泥盆纪-三叠纪岩相古地理格局及碳酸盐岩的形成与消亡时间提供了重要证据。 The standard profile of Lanmu formation, named by Lu Zhongqiu and others from the former Guangxi Petroleum Census Group in 1961, is located in Lanmu area of Donglan National Geopark, the lithology of which is fine sandstone, siltstone interbedded with mudstone, flysch, flyschoid cyclothem, with complex sedimentary structure, and various incomplete Baoma Sequences, bottom cast structure and flow deformation structure are common. Rich in ammonites, hornstones and bivalves and other biological fossils. The discovery of the Lanmu formation provides important evidence for interpreting the Devonian – Triassic lithofacies paleogeography pattern and the formation & extinction time of carbonate rocks in Northwest Guangxi.