塔里木盆地覆盖区寒武系生物地层研究新进展

NEW ADVANCES IN CAMBRIAN BIOSTRATIGRAPHY OF THE COVERED AREA OF THE TARIM BASIN

全球有关寒武系生物地层的材料大都来自露头区,而鲜见于钻井材料。依据塔里木盆地中石化的11口探井及中石油的库南1井,报道寒武系生物地层研究方面取得的一些新进展:发现小壳化石、微古植物等15个门类的微体化石(小壳类及牙形类58属73种,微古植物29属30种),其中软舌螺类Paragloborites,Circotheca,Lo-photheca,Torellella等9属14种,双壳类Praelomellodonta,腹足类Barskovia,Auriculaspira,Scenella,管壳类Zhiginites,Sachites,开腔骨Chancelloria,浙江棒Zhejiangurhadion以及未定类Aegides和遗迹化石等,均为井下寒武系的首次发现。结合岩石、测井、地震地层等综合研究后,首次在塔里木盆地覆盖区寒武系建立相关生物地层序列,从而不仅可将塔里木盆地的寒武系进行统一划分和对比,也可与滇东、下扬子地区以及邻国哈萨克斯坦等露头区的寒武系进行对比。

Cambrian biostratigraphic data of the Tarim Basin are chiefly from outcrops.This paper reports the latest advances in Cambrian biostratigraphic research of the Tarim Basin based on data from 11 SINOPEC wells and the CNPC Kunan 1 well.From the borehole samples,we have recovered 15 groups of Cambrian microfossils,including 58 genera and 73 species of small shelly fossils and conodonts,as well as 29 genera and 30 species of organic-walled microfossils.These fossils include hyoliths（e.g.Paragloborites,Circotheca,Torellella）,bivalves（e.g.Praelomellodonta）,gastropods（e.g.Barskovia,Auriculaspira,Scenella）,disarticulated sclerites（e.g.Zhijinites,Sachites）,Chancelloria,sponges（e.g.Zhejiangorhabdion）,Aegides,and trace fossils.Combined biostratigraphic,lithostratigraphic,well log,and seismic stratigraphic data can be used to correlate the Cambrian strata in the Tarim Basin with those in East Yunnan of the lower Yangtze region and in Kazakhstan.