西秦岭甘、川交界处海相志留一泥盆系成连续沉积,以细碎屑岩为主夹少量碳酸盐岩。川西北若尔盖县普通沟、羊路沟和甘南迭部下吾那沟等剖面内界线位于上志留统羊路沟组与下泥盆统下普通沟组之间。羊路沟组为碳酸盐岩夹细碎屑岩,厚110—177.5米,含有丰富的各类化石。其中四射珊瑚可划分为下部Entelophyllia-Pilophyllum组合带和上部Denayphyllum-Chavsakia组合带,包括有37属,大部分是晚志留世常见属种。床板珊瑚亦可划分为下部Laceripora dictyosa-Palaeocorolites xiawunaensis-Mesofavosites yanglugouensis-Squameolites gigantea组合带和上部Emmonsiella saaminicus-Squameopora sichuanensis-Squameofavosites sokolovf组合带, West Qinling Gansu, Sichuan at the junction of marine Zhili a Devonian into a continuous deposition, mainly composed of fine clastic rocks a small amount of carbonate rocks. The boundaries of the Gouguogou, Yangluogou and Gansu Diego Günigou etc sections in Zoige County, northwestern Sichuan are located between the Upper Silurian Yangluogou Formation and the Lower Devonian Ordinary Gouge Formation. Yangluogou carbonate clastic fine clastic rocks, thickness 110-177.5 meters, is rich in various types of fossils. The coral can be divided into the lower Entelophyllia-Pilophyllum and the upper Denayphyllum-Chavsakia, including 37 genera, most of which are Late Silurian common species. Bedplate corals can also be divided into the lower Laceripora dictyosa-Palaeocorolites xiawunaensis-Mesofavosites yanglugouensis-Squameolites gigantea assemblage and the upper emmonsiella samasicus-Squameopora sichuanensis-Squameofavosites sokolovf assemblage,