塔中I号断裂带顺6井上奥陶统取芯段古生物群落演化及其古生态意义

本文研究了塔中I号断裂带西北端顺6井上奥陶统地层第一次取芯段的古生物群落,共划分出5种类型:分别为隐蓝细菌群落、海德菌-疑源类-四分珊瑚群落、四分珊瑚-海得菌群落、四分珊瑚-红藻类稀群落、棘皮类稀群落,各群落的生物组成均不同。确定礁群落有3种:隐蓝细菌群落、海德菌-疑源类-四分珊瑚群落和四分珊瑚-海得菌群落。隐蓝细菌群落发育于台地边缘较深水的灰泥丘,海德菌-疑源类-四分珊瑚和四分珊瑚-海德菌群落发育于台地边缘较浅水的生物礁,红藻类稀群落和棘皮类稀群落发育于台地边缘滩。灰泥丘、四分珊瑚骨架礁和海德菌障积礁地层溶蚀孔洞很发育,但是均被亮晶方解石充填。生屑砂屑滩中的溶孔具有残余孔隙,可能构成油气的储集空间。

Evolution and palaeoceological significance of the paleobiocoenosis from the Upper Ordovician strata in the Shun-6 well, central Tarim Basin

The paleobiocoenosis from the Upper Ordovician strata in the Shun-6 well,central Tarim Basin are grouped into five types： cyanobacteria community,Hedstroemia-problematicum-Tetradium community,TetradiumHedstroemia community,Tetradium-Solenopora community and echinoderm community. Three reef communities include cyanobacteria community,Hedstroemia- problematicum-Tetradium community and Tetradium-Hedstroemia community. The cyanobacteria community lived on the deep-water mud mounds on the platform margins. The Hedstroemia-problematicum-Tetradium community and Tetradium-Hedstroemia community lived in the shallow-water organic reefs on the platform margins. The rare Solenopora community and echinoderm community lived on the platform-margin banks. The mud mounds,Tetradium framework reefs and Hedstroemia reefs have abundant dissolution pores,but all the pores are filled with sparry calcite. There are residual pores in the bioclastic limestones of the bank facies,which has the potential to form the hydrocarbon reservoirs.