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2014年对豫西淅川县境奥陶纪、志留纪地层考察后取得如下认识:1)上奥陶统碎屑岩相地层(如上集王罐沟)宜统称为蛮子营组,灰岩、泥岩相(如大石桥石燕河)从下到上宜称为杨庄村组、石燕河组和刘家坡组;2)根据腕足类,石燕河组(含Rongatrypa动物群)和张湾组下部(含Cathaysiorthis动物群)分别归于晚奥陶世凯迪中晚期和志留纪兰多维列世鲁丹早中期,推测本区缺失凯迪阶顶部、赫南特阶和鲁丹阶底部地层;3)Cathaysiorthis动物群的发现说明本区发育比Pristiograptus leei带更低的地层;4)若岞■组属于早奥陶世的结论可信,则本区缺失中奥陶统,约有10 Myr未接受海相沉积;5)晚奥陶世华北型和北美中大陆型的牙形类与中、东亚腕足动物群和志留纪初期典型华南型腕足动物群的发育表明,当时北美、中东亚的许多块体位于热带海域,由于北美与我国许多块体相距甚远,腕足动物交流受限明显,但牙形类可沿着赤道环流交流。4.5亿年前后,本区在地层序列、地质发展史、沉积环境、生物相和生物组合特性上,情况较复杂,上奥陶统的似更近似于华北,而志留系的与华南关系更密切,并很可能一直持续到泥盆纪晚期。
In 2014, following the investigation of the Ordovician and Silurian strata in Xichuan County, western Henan Province, the following observations were made: 1) The Upper Ordovician clastic lithofacies (such as Shangji Wanganggou) should be collectively referred to as the Manzi Formation, limestone, The mudstone facies (such as Shiyan River in Dashiqiao) should be referred to as Yangzhuangcun Formation, Shiyanhe Formation and Liujiapo Formation from bottom to top. (2) According to Brachiopods, Shiyanhe Formation (including Rongatrypa fauna) and the lower part of Zhangwan Formation (including Cathaysiorthis Fauna) to the Late Ordovician Kaidi and Late Silurianland multidimensional Lidan early Mesozoic, suggesting that the area lacked the top of Kaidi, Hernández and Rudan order; 3) the discovery of Cathaysiorthis fauna Indicating that the area is lower than that of the Pristiograptus leei belt; 4) if the conclusion of the 组 group belongs to the Early Ordovician, then the Middle Ordovician is missing in this area and about 10 Myr is not accepted for marine sedimentation; 5) The development of late-Ordovician North China and North America Meso-Continental conodonts, Middle East and East Asia Brachiopods and the typical South China Brachiopods in the early Silurian suggest that at that time many blocks in North America, Middle East and East Asia were located in the tropics, Many blocks in North America and our country are far apart, Brachiat animal exchanges by Clear, but may be shaped teeth alternating along the equatorial ring current class. About 450 million years ago, the area is more complex in sequence of stratigraphy, history of geological development, sedimentary environment, biological facies and biological assemblage. The Upper Ordovician seems to be more similar to North China, while the relationship between Silurian and South China is more Closely, and most probably up to the late Devonian.