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志留纪兰多维列世时扬子地台的陆表海的各部分先后上升为陆，至特列奇期末仅在局部地区残留海湾，其西北缘的宁强湾就是其中之一。在相当于ｇｒｉｅｓｔｏｎｅｎｓｉｓ带上部和ｓｐｉｒａｌｉｓ－ｇｒａｎｄｉｓ笔石带的宁强组内沉积了２０００多米厚的泥页岩夹碳酸盐岩，底栖生态组合指示的深度浅于潮下带下部。基底的快速沉降和来自周缘不同时期隆起区陆源碎屑的强烈均衡补偿充填是宁强湾沉积的主要特征。宁强湾开口于西面的广海，其它三面由大巴山率先升隆区和西乡上升区环绕，在陆源碎屑干扰较弱的时期和地点形成了局限碳酸盐岩台地的沉积建造。宁强组碳酸盐岩地层可分为８个主要形成期，每期形成的局限台地在不同部位发育了各种类型的生物岩隆，各期碳酸盐岩台地都是由于大量陆源碎屑泥质的盖覆而结束。宁强组的顶界从东北向西南穿时，指示了扬子地台西北缘在特列奇期末由东北而西南的最后抬升过程。
The parts of the surface sea of the Yangtze Platform at the time of the Silveradian Multi-dimensional Worlds have risen to land one after another, leaving the Gulf at the end of the special period only in some areas and the Ningqiang Bay in the northwestern margin. Sedimentary carbonate shale was deposited more than 2000 m thick in the Ningqiang Formation, which corresponds to the upper part of the griestonensis belt and the spiralis-grandis pendera, indicating that the depth of the benthic assemblage is shallower than the lower part of the subtidal zone. The rapid subsidence of the basement and the intense balanced compensation filling of terrigenous debris from the uplifts in different periods of the periphery are the main features of deposition in Ningqiangwan. Ninghai Bay is open to the west of Guanghai. The other three sides are surrounded by the first Dabashan uplift and the Xixiang uplift, forming the depositional confined carbonate platform during periods and sites where the terrestrial interference was weak. The Ningqiang Formation carbonate rock strata can be divided into 8 major formation periods. Each of the limited platforms formed in each stage developed various types of bio-rock deposits in different parts. The carbonate platform in each stage is due to a large amount of terrigenous debris The muddy cover over. The top of Ningqiang Formation, when it passed from northeast to southwest, indicated the final uplifting process from northeast to southwest of the northeastern margin of Yangtze platform at the end of the Tegerchian period.