新疆三塘湖盆地塘浅3井中侏罗世孢粉组合

MIDDLE JURASSIC SPOROPOLLEN ASSEMBLAGES FROM TANGQIAN-3 WELL OF THE SANTANGHU BASIN, XINJIANG

本文对在新疆三塘湖盆地塘浅 3井 10 6— 70 1m层段发现的孢粉化石进行了系统的分析研究 ,共获孢子花粉5 2属 12 0种 (包括相似种和未定种 ) ,疑源类化石 2属 2种及一个未定类型 ,根据孢粉属种及其含量的变化 ,自下而上分为两套组合 :1) Cyathidites minor- Osmundacidites- Cycadopites- Quadraeculina组合 ;2 ) K raeuselisporites ma-nasiensis- Classopollis- Quadraeculina组合。第一组合产于该井 4 13— 70 1m层段 ,时代归为中侏罗世早期 ,赋存地层相当于西山窑组 ;第二组合产于 10 6— 4 13m,时代归为中侏罗世晚期 ,赋存地层相当于头屯河组。系统分析组合中主要孢粉属种及其母体植物的生长环境 ,推测新疆三塘湖盆地及其周围地区在中侏罗世早期为温带或亚热带气候 。

Abundant sporopollen of about 120 species referred to 52 genera and some acritarches (2 species of 2 genera and 1 indeterminate type) were disco vered from Tangqian 3 well of the Santanghu basin, Xinjiang. They are grouped into two assemblages namely Cyathidites minor Osmundacidites Cycadopites Quadraeculina assemblage, Kraeuse lisporites manasiensis Classopollis Quadraeculina as semblage. Based on the assemblages, the author considers the first assemblage to be early Middle Jurassic in age, and the second assemblage to be late Middle Jurassic. During early Middle Jurassic the climate was warm and wet in the Santanghu basin of Xinjiang, in a temperate—subtropical zone. During late Middle Jurassic the climate was also warm, but became drier than early Middle Jurassic, in a subtropical zone.