东天山库姆塔格沙垄地区企鹅山群的解体及岩石地层单位厘定

东天山企鹅山群的组级岩石地层单位厘定争议已久.1∶5万区域地质矿产调查, 于库姆塔格沙垄地区企鹅山群中的两套碳酸盐岩中, 分别发现了牙形刺Streptognathodus suberectus, Idiognathoides sinuata和珊瑚Pelalaxis intermedia, Lithostrotionella rarivesicula, Fomichevella kiaeri, 确认其时代分属晚石炭世罗苏阶-达拉阶和达拉阶-小独山阶, 分别重新厘定为底坎尔组和脐山组.由该两组沉积地层隔离的两套火山岩, 空间上分布相对固定, 岩石组合特征明显, 野外极易识别和区别, 大区易于对比, 且分属早石炭世和晚石炭世.库姆塔格沙垄地区企鹅山群可进一步解体并由老到新厘定为小热泉子组、底坎尔组、企鹅山组和脐山组等4个组级岩石地层单位. 

On Disintegration of Qi'eshan Group and Its Definition of Lithostratigraphic Units from Kumutag Sand-Ridge Area in the Eastern Tianshan

The debate of the definition of lithostratigraphic units in formation scale in eastern Tianshan was presented long before.During 1∶50000 regional geology and mineral survey, some conodonts fossils such as Streptognathodus suberectus, Idiognathoides sinuate etc.and coral fossils such as Pelalaxis intermedia, Lithostrotionella rarivesicula, Fomichevella kiaeri were discovered in the two limestones of the Qi'eshan Group from Kumutag sand-rigde.The age of conodont fossils within the stratum was determined as the Upper Carboniferous Luosu Stage-Dalaan Stage, and the age of coral fossils within the stratum was confirmed as the Dalaan Stage-Xiaodushan Stage.Therefore, they belong to Dikan'er Formation and Qishan Formation.The two volcanic rocks separated by two sedimentary rocks have some characteristics such as regular distribution in space, diagnostic rock association, distinguishable in field geolgy and comparable in study area.And their ages are Early Carboniferous and Late Carboniferous respectively.Therefore, the Qi'eshan Group can be further divided into four lithostratigraphic units according to formation scale from early to late, which are Xiaorequanzi Formation, Dikan'er Formation, Qi'eshan Formation and Qishan Formation.