塔里木盆地中中新世有孔虫群及其生态和生油性分析

THE ANALYSIS ON MIDDLE MIOCENE FORAMINIFERAL FAUNA OF THE TARIM BASIN AND THEIR ECOLOGY, PROPERTY OF STRATIGRAPHIC OIL—SOURCE POTENTIAL

裘松余

Qiu Songyu

地矿部吉林石油普查勘探指挥所

Jilin Headquarters of Petroleum Exploration, Ministry of Geology and Mineral Resources

塔里木盆地中中新统以杂色碎屑岩为特征,主要有砂岩、粉砂质泥岩和泥岩。呈灰色、灰绿色与棕色、红棕色相间形成"杂色条带"。有孔虫材料主要采自喀什坳陷,分别为安居安组和吉迪克组。中中新世卷转虫群大量而广泛地分布在两个近东西向条带区。即喀什坳陷的乌恰至小阿图什、库车拗陷的库车河至库尔勒。这个有孔虫群与Cyprideis littoralis, Cyprinotus dcformis,Limnocythere orgu lata,Cyclocypris sp.,Eucyris sp.及个别轮藻化石共生,故认为是半咸水过渡相有孔虫群,反映为淡化泻湖环境;该沉积对生油较为有利。

The middle Miocene sequences in the Tarim Basin are characterized by the clastic deposits comprising mainly of sandstone,siltstone-mudstone and mudstone with the appearance of variegated zones interspaced with grey and greyish green and brownish and reddish brown.Foraminiferal materials sourced mainly from the Kashi Depression and the Kuche Depression,are attributed to the Anjuan Formation and the Jidike Formation.The ammonia fauna of the middle Miocene sequences widespread over the two near E-W striking belts,i.e the Kashi Depression from Wuqia to Xiao’atushi,and the Kuche Depression from Kuche river to Kuele respectively.The Foraminiferal fauna are associated with Cyprideis,littoralis,Cyprinotus deformis,Limnocythere orgulata,Cyclocypris sp.,Eucypris sp.,etc and in addition,specif ic fossils of charophytes.This fauna would survive in the environment of brackish-fresh transitional water,which is favourable for oil generation.

https://doi.org/10.11781/sysydz199001087