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西秦岭泥盆系分布广泛,其中迭部县当多沟、若尔盖县普通沟一带剖面完好,层序清楚,总厚3700余米。由上志留统至下石炭统基本成连续沉积,其岩石地层单位由上而下是:下石炭统益哇组、上泥盆统陡石山组、擦阔合组、中、上泥盆统蒲莱组(新建),中泥盆统下吾那组、鲁热组,下、中泥盆统当多组,下泥盆统尕拉组、上普通沟组、下普通沟组,上志留统羊路沟组(新建)。通过十三个门类的研究,建立了部分门类的生物层序,它们为地层时代的确定和区内外同类地层的对比提供了重要依据。根据部分化石组合带的对比表明,本区生物群与华南象州型泥盆系的生物群有较密切的关系。志留一泥盆系界线位于羊路沟组与下普通沟组之间,以牙形刺Icriodus woschmidti/Ligonodina elegans;腕足类Protathyris praecursor延限带/Molongia-Atrypoidea组合带,四射珊瑚Neomphyma-EmboIophyllum组合带/Denayphyllum-Chavsakia组合带;
The Devonian in the West Qinling is widely distributed. The Dangdou County Dangdougou and the Ruoergou Ordosgou have a well-preserved section and a clear sequence with a total thickness of 3,700 meters. Basis of the Upper Silurian to Lower Carboniferous basically deposited continuously, and its lithostratigraphic units from top to bottom are: Lower Wadi Formation, Upper Devonian Doushishan Formation, Macadam Group, Middle and Upper Devonian Pulai Formation (newly built), the Lower Devonian Group in the Middle Devonian, the Luhe Formation, the Lower Middle Devonian Dado Formation, the Lower Devonian Garra Formation, the Upper Ordinary Ditch Formation, the Lower Ordinary Ditch Formation, Li Tuo Yang Lugou group (new). Through the research of thirteen categories, the biological sequences of some categories have been established, which provide an important basis for the determination of stratigraphic age and the comparison of similar strata inside and outside the area. According to the comparison of some fossil assemblages, the biota in this area has a close relationship with the biota in the Xiangjiang Devonian in southern China. The Silurian-Devonian line is located between the Yangluogou Formation and the Lower Ordos Formation, with the conodonts Icriodus woschmidti / Ligonodina elegans, the brachiopod Protathyris praecursor extension zone / Molongia-Atrypoidea combination zone, the coral Neomphyma-EmboIophyllum Combination band / Denayphyllum-Chavsakia combination band;