南秦岭淅川地区上石炭统周营组有多门类化石共生 ,类为晚石炭世的标准分子 ,菊石、腕足、珊瑚、双壳、腹足类多具泥盆纪生物群特征。岩石组合、岩性特征、层序特征、沉积环境演变及构造古地理、生态的综合研究表明 ,周营组为晚石炭世沉积地层 ,其内的晚石炭世、中晚泥盆世古生物组合是在有障壁的局限滞留盆地这一特殊的古地理和生态环境下形成和发展起来的 ,是南秦岭淅川地区特有的组合 ,不具有搬运再沉积的物质条件 ,不是搬运再沉积的结果。每一次海侵 ,海水的加深和有机质的富集 ,是周营组生物群得以发生和发展的有利条件。海水的退出、咸化和相对闭塞环境下食物的缺乏 ,是生物群绝灭 ,并很好保存埋藏的主要原因。 There are many types of fossil symbiosis in the Upper Carboniferous Zhouying Formation in the Xichuan region of the South Qinling Mountains. The clam class is the standard member of the Late Carboniferous. The ammonites, brachiopods, corals, bivalves and gastropods are all characterized by the Devonian biota. The combination of lithology, lithology, sequence features, evolution of sedimentary environment and tectonic palaeogeography and ecology indicate that the Zhouying Formation was a Late Carboniferous sedimentary formation, and the Late Carboniferous and Late Devonian paleobiosses Formed and developed in the special paleogeography and ecological environment of the confined stranded basins with faulty walls are the unique combination of the Xichuan region in the South Qinling Mountains. They do not have the material conditions of handling and redeposition and are not the result of handling and redeposition. Each transgression, the deepening of seawater and the enrichment of organic matter are favorable conditions for the occurrence and development of the biota in the Zhouying Formation. Seawater withdrawal, salinization and the relative lack of food in the closed environment are the major causes of extinction of the biota and good conservation of burial.