论文部分内容阅读
本文详细介绍了湖南江华地区晚泥盆世和早石炭世牙形刺的地层分布特征,将它们自下而上归为5个带和4个组合带。其中 lcriodus-Protognathodus meischneri 组合带主要分布于孟公坳组下部,且与珊瑚 Cystophrentis 共生;Siphonodella simplex 带,S.sinensis 带和 S.eurylobata-S.isosticha 带分布于孟公坳组的中部和上部;Polygnathus communis carinus 带和 Scaliognathus anchoralis 带分布于大圩组。根据牙形刺研究和国际间的地层对比,作者认为 IcrioduS-Protognathodus meischneri 组合带应当归于上泥盆统,这就意味着孟公坳组下部产珊瑚 Cystophrentis 的地层的时代应当为晚泥盆世。Siphonodella simplex 可能代表一种与 S.sulcata 同时出现、平行发展的生态类型,因此可作为浅水相区泥盆—石灰系界线的标志,孟公坳组的中部和上部仍归于下石炭统。此外,作者还以大量事实论述了岩关阶内部事件的性质、表现形式、发生时间以及与某些磷、锰沉积的关系。
In this paper, the stratigraphic distribution characteristics of the Late Devonian and Early Carboniferous conodonts in the Jianghua area of Hunan Province are described in detail. They are classified into 5 belts and 4 belts from bottom to top. Among them, the lcriodus-Protognathodus meischneri assemblage belonged to the lower part of the Menggongao Formation and coexisted with Cystophrentis. Siphonodella simplex, S. sinensis and S..eurylobata-S.isosticha belts were distributed in the middle and upper part of the Menggongao Formation. Polygnathus communis carinus belt and Scaliognathus anchoralis belt distributed in the Daxu group. According to the conodont research and international stratum comparisons, the author believes that the IcrioduS-Protognathodus meischneri assemblage should be attributed to the Upper Devonian, which means that the age of the strata of the lower coral Cystophrentis in the Menggongao Formation should be Late Devonian. Siphonodella simplex may represent a type of ecology that appears parallel to S.sulcata and develops in parallel. Therefore, Siphonodella simplex can be used as a marker for the Devonian-Lime boundary in the shallow-water facies. The middle and upper parts of the Menggongao Formation still belong to the Lower Carboniferous. In addition, the author also discusses the nature, manifestation, time of occurrence and some relations with certain phosphorus and manganese deposition in a large number of facts.