中国科学院南京地质古生物研究所机构知识库

贵州省惠水县王佑至翁赖一带出露的中泥盆世晚期浅海底栖相地层翁赖组(新名)陆源碎屑发育,沉积厚度巨大,单体珊瑚居多。由于受到当地穹窿地质构造的影响,只出露了中泥盆统的最上部,即相当于独山剖面的独山组鸡窝寨段和宋家桥段这二段地层,而相当于鸡泡段及其以下的地层都被掩埋在地下。根据岩性和珊瑚群组合面貌,翁赖组可以分成上、下两个部分:下部砂岩比较多,也有少许灰岩和泥质砂岩,大致可与独山剖面的独山组宋家桥段相当;上部虽然也有砂岩和泥质砂岩,但灰岩和泥质灰岩明显增加,最富有生物地层学意义的是在上部之底发现了中泥盆世晚期的标准珊瑚化石Sinospongophyllum,表明它可与独山剖面的独山组鸡窝寨段进行对比。无独有偶,独山县的泥盆系剖面是以群体的内板珊瑚(Endophyllum)层作为鸡窝寨段的底界的,Endophyllum层之上是鸡窝寨段(灰岩);Endophyllum层之下则是宋家桥段(砂岩)。Sinospongophyllum(单体珊瑚)与Endophyllum(群体珊瑚),虽然它们外部形态不同,但它们的骨骼内部构造基本上是相同的或者是非常相似的,而它们外形的差异主要是受不同海洋生态环境(如海浪的强弱和陆源碎屑物的多少)影响的结果。文中描述了翁赖组下部的四射珊瑚,共有6属7种,含2个新种,分别是:Grypophyllum cf.primum Wedekind,Grypophyllum wangyouense(Li in Kong and Huang),Cyathophyllum wenglaiense sp. nov.,Sinodisphyllum litvinovitshae(Soshkina),Temnophyllum majus Walther,Argutastrea quadrigemina(Goldfuss)和Ceratophyllum simplex sp. nov.。它们都是华南以及亚洲、欧洲、澳大利亚和北美西部等地中泥盆世晚期常见的一些珊瑚属种。

Wangyou of Huishui County and Dushan County are the two best localities in well-developed Devonian sequences in the south of Guizhou Province. They are characterized by the occurrences of abundant fossils and solid research foundations. The thick late Middle Devonian shallow marine deposits exposed in Wangyou of Huishui County is composed of mainly terrestrial debris and its corals are dominated by solitary rugose corals, while the sequences in Dushan County are characterized by carbonates intercalated with siliceous clasts that are not very thick,and the possession of both colonial and solitary corals.Based on the Middle Devonian biostratigraphic work,it is proposed that the occurrence of the solitary rugose coral Sinospongophyllumcan be an important boundary for stratigraphic divisions of the regions:the lower part of the Wenglai Formation occurs below Sinospongophyllum-bearing horizon,correlative to the Songjiaqiao Member in the outcrops of the Dushan County,while the upper part of the Wenglai Formation occurs above Sinospongophyllum-bearing horizon,correlative to the Jiwozhai Member in the outcrops of the Dushan County, as below the Sinospongophyllum layers,the sequences were named Songjiaqiao Member and the appearance of Sinospongophyllum indicated the start of the Jiwozhai Member in Dushan County.The solitary Sinospongophyllum and colonial Endophyllum bear similar internal skeletons,with the difference in their external morphologies,suggesting that they lived in different marine environments.The present study describes 7 species of 6 genera of rugose corals from the lower part of the Wenglai Formation:Grypophyllum wangyouense(Li in Kong and Huang),Grypophyllum cf.primum Wedekind,Cyathophyllum wenglaiense sp.nov.,Sinodisphyllum litvinovitshae(Soshkina),Temnophyllum majus Walther, Argutastrea quadrigemina(Goldfuss), and Ceratophyllum simplexsp.nov.The corals from the upper part of the Wenglai Formation will be addressed in future works.