朝鲜半岛中部的志留系特征及其地质意义

Characteristics of the Silurian System in the middle part of the Korean Peninsula and their significance

朝鲜半岛的志留系仅见于中朝克拉通东缘朝鲜半岛中部的平南盆地。该盆地志留系发育于谷山—新溪—遂安地区和法洞地区。谷山—新溪—遂安地区的志留系划分为碎屑-碳酸盐岩组成的谷山组和碳酸盐岩为主的月阳里组,化石非常丰富,包括珊瑚类、腕足类、海百合类和腹足类等,该地区谷山组中部和月阳里组上部发育以床板珊瑚为主的生物礁。法洞地区志留系主要为碎屑岩,夹碳酸盐岩薄层,化石极少。将平南盆地志留系生物地层划分为5个组合带,自下而上依次为Striispirifer shiqianensis带、Palaeofavosites balticus-Camarotoechia ubsuensis组合带、Favosites songrimensis-Leptostrophia guizhouensis组合带、Parastriatopora coreanicus-Pleurorima granata组合带和Pentagonocyclicus monocostatus-Pentagonopentagonalis probus组合带。据此认为谷山组时代为兰多维列世,月阳里组时代为温洛克世—罗德洛世。

The Silurian System of the Korean Peninsula is only found in the Pyongnam Basin in the middle part of the Korean Peninsula,at the eastern edge of the Sino-Korean Craton and distributed in the GoksanXingye-Suan and Popdong areas.In the Goksan-Xingye-Suan area,the system is subdivided into two formations：the Goksan Formation comprising mainly clastic-carbonate rocks,and Wolyang-ri Formation containing primarily carbonate rocks with abundant animal fossils—corals,brachiopods,crinoids,gastropods and others.Organic reefs developed in the middle and upper parts of the Goksan and Wolyang-ri Formations,respectively,dominated by tabulate corals.In comparison,the Silurian System in the Popdong area is mainly composed of siliciclastic rocks and thin layers of carbonate rocks with very few fossils.The Silurian biostratigraphic zonation in the Pyongnam Basin is subdivided into five assemblage zones from bottom to top：Striispirifer shiqianensis, Palaeofavosites balticus-Camarotoechia ubsuensis, Favosites songrimensis-Leptostrophia guizhouensis,Parastriatopora coreanicus-Pleurorima granata and Pentagonocyclicus monocostatus-Pentagonopentagonalis probus assemblage zones.Therefore,we propose that the geological ages of the Goksan and Wolyang-ri Formations are the Llandovery and Wenlock-Ludlow Epochs,respectively.