陕南川北志留系兰多维列统特列奇阶宁强组的生物礁

志留纪兰多维列世（Llandovery）扬子地台持续上升。特列奇期（Telychian）griestoniensis笔石带上部至spiralis-grandis带代表的时限内，地处扬子地台西北缘的宁强湾，在温暖浅海的环境中沉积了宁强组巨厚的泥页岩，其中夹含8套碳酸盐岩。在与之对应的8期小型局限碳酸盐岩台地的不同部位建造了生物礁和生物滩。生物礁的类型包括骨架礁、生物层和灰泥丘。生物礁群落由底栖固着的造礁珊瑚、苔藓虫、海百合、藻类、层孔虫，以及非固着的附礁生物腕足类、鹦鹉螺、三叶虫等组成。通过宁强广元地区不同地点和层位的生物礁组合分析，论述它们在生态组合、生长形状和发育过程中的多样性。

The Reef Complexes of Ningqiang Formation, Telychian,Ningqiang Guangyuan Area

The uplifting of whole Yangtze platform occured by the end of Llandovery (Telychian), execpt sev-eral bays around the margin of the platform. The Ningqiang Formation consists of more than 2000 m shales and limestones with faunas form upper griestoniensis Zone to spiral is-grandis Zone. The limestones within this unit may be subdivided into 8 stages according to their origination in ascending order. Reef complexes developed at differentsites on limited carbonate platforms. Reefs, biostromes and lime-mud-mounds cropped out in the different subfacies of the reef complexes. The important reef complexes'building organisms include corals, bryozoans, pelmatozoans, algea and stromatoporoids, and the at tach-ing- reefal organisms are brachiopoda, nutiloidea, trilobite, etc.. The features of the reefal organisms are changable in temporal and spatial distribution. Analysis of typical reef complexes indicate that they are variable in association, shape and growth process. The termination of all limited platforms and reef com-plexes depends on the covering of mudstones.