吐-哈盆地侏罗系孢粉研究

STUDY OF THE JURASSIC SPORES AND POLLENSIN TURPAN-HAMI BASIN

本文研究了吐-哈盆地侏罗系各层位的孢粉化石分布特征,认为可以划分出六个孢粉组合:八道湾组的原始松柏粉属Protoconiferus-苏铁粉属Cycadopites-四字粉属Quadraeculina组合;三工河组的桫椤孢属Cyathidites-苏铁粉属Cycadopites-四字粉属Quadraeculina组合;西山窑组的桫椤孢属Cyathidites-四字粉属Quadraeculina-苏铁粉属Cycadopites组合;三间房组的桫椤孢属Cyathidites-克拉梭粉属Classopollis-紫萁孢Osmundacidites组合;七克台组的克拉梭粉属Classopollis-桫椤孢属Cyathidites-双束松粉属Pinuspollenites组合;齐古组的克拉梭粉属Classopollis-双束松粉属Pinuspollenites组合。此项研究为该区地层划分、对比提供了古生物依据。

According to the distribution features of Jurassic spore-pollen fossils from Turpan-Hami Basin six spore and pollen assemblages have been divided. In ascending order, they are: 1. Protoconi ferus-Cycadopites-Quadraeculina assemblage. 2. Cyathidites-Cycadopites-Quadraeculina assemblage. 3. Cyathidites-Quadraeculina-Cycadopites assemblage. 4. Cyathidites-Classopollis-Osmundacidites assemblage. 5. Classopollis-Cyathidites-Pinuspollenites assemblage. 6.Classopollis-Pinuspollenites assemblage. The six assemblages exist in the six formations: Badaowan, Sangonghe, Xishanyao, Sanjianfang, Qiketei and Qigu formations respectively. Therefore, this study provides a basis for the reconstruction of the local paleoclimate. The lower Jurassic was a favourable coal forming period and, during the mid upper stages, the paleoclimate became dry gradually.