准噶尔盆地彩参2井侏罗纪孢粉化石及层序地层分析

对准噶尔盆地彩参 2井侏罗纪孢粉化石研究表明 ,八道湾组具有deltoidospora cycadopites protoconiferus classopollis组合 ,三工河组具有cyathidites osmundacites pinuspollenites classopollis组合 ,西山窑组为cyathidites dic tyophyllidites cycadopites perinopollenites组合 ,石树沟群为cyathidites klukisporites classopollis concentrisporites组合 ,它们对地层时代有较好的指示意义。对孢粉古生态和沉积岩颜色、岩性及粘土矿物成分综合研究表明 ,研究区八道湾为暖温带潮湿气候 ;三工河早期为亚热带干旱、半干旱气候 ;三工河中晚期至西山窑期为亚热带潮湿气候 ;石树沟群早期为亚热带半干旱气候 ,但发生过两次时潮时旱的气候波动 ,石树沟群晚期气候干旱炎热 ,并促使湖盆急剧收缩、消亡。侏罗系可划分为 6个层序 ,层序界面附近的孢粉丰度及分异度最小 ,而最大湖侵期的孢粉丰度及分异度最大

ANALYSES OF SPORO-POLLEN FOSSILS AND SEQUENCE STRATIGRAPHY OF WELL CAICAN-2 IN THE JUNGGAR BASIN IN THE JURASSIC PERIOD

The sporo\|pollen association of Badaowan formation is \?ltoidospora\|cycadopites\|protoconiferuss\|classopollis. \%The association of Sangonghe formation is \%cyathidites osmundacites\|pinuspollenites\|classopollis. \%Xishanyao formation is \%cyathidites\|dictyophyllidites\|cycadopites\|perinopollenites, \%and Shishugou formation is \%cyathidites\|klukisporites\|classopollis\|concentrisporites. \% These associations are of chronostratigraphic significance. Comprehensive studies of paleoecologic habits of sporo\|pollens, lithologic characters and the clay mineral constitution show that there has been a warm humid climate in the Badaowan period, and a short term of hot and dry climate in early Sangonghe period, and a warm\|humid climate again from the middle Sangonghe to Xishanyao period. In the early Shishugou period, the climate became semi\|arid with two small undulations, and later, the climate became arid, which had a great contribution to the contraction of the Jurassic lake area. The Jurassic system of the study area is divided into six stratigraphic sequences. Content and differentiation of sporo\|pollens are the smallest near sequence boundaries, but the biggest in the largest transgressive period.