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宜昌黄花场宜黄1井钻遇牯牛潭组上部灰岩地层,属中奥陶统达瑞威尔阶顶部,自下而上出现棕灰色生屑泥粒状灰岩、棕红色生屑粒泥状灰岩、灰色瘤状灰岩、棕红色生屑粒泥状灰岩、棕灰色与灰色生屑粒泥状灰岩夹含少量泥质条带的灰色生屑泥状灰岩。以碳酸钙灰泥和粉砂屑基质沉积为主,见少量细颗粒破碎程度高的三叶虫、介形类、棘皮类等后生动物化石碎片,部分层位的生屑颗粒长轴无定向排列,它们在偏深水区安静海底堆积后无动荡水流频繁改造,顶部的生物扰动现象可能与海退有关。牯牛潭组上部没有典型暖水浅水相的化石类型和内碎屑颗粒沉积,灰岩均形成于最大浪基面之下水温偏凉的开阔陆表海区。
Yichang Huanghuashan Yihuang-1 well met the upper Limestone formation in the Nianniu Tan Formation, which belongs to the top of the Daruweir Alta Ordovician stepstone. From bottom to top, it appears brown-gray, bioclastic, grained limestone, Limestone, gray knobby limestone, reddish brown crushed limestone, brownish gray and gray crushed limestone, and gray crusted muddy limestone with small amount of muddy band. Calcium carbonate stucco and silt matrix deposition, see a small amount of fine particles of a high degree of trilobite crust, Ostracoda, echinoderm and other metazoan fossil fragments, some layers of long-axis orientation of the non-directional arrangement of crumbs , They are frequently unchanging water flow after the quiet seabed accumulation in the deep-water area, and the top of the biological disturbance may be related to the regression. In the upper part of 牯Niu Tan group, there is no typical fossil type of warm water and sedimentary debris deposition in the upper part. Limestone is formed in the open sea surface area where the water temperature is cool below the maximum wave surface.