合肥盆地朱巷组孢粉组合及其地质时代和古植被古气候

合肥盆地位于安徽省中部,面积约21000平方公里,是安徽省最大的中、新生代沉积盆地。盆地内以白垩系最为发育,白垩系分为朱巷组和响导铺组。笔者系统地研究了朱巷组的孢粉化石。本文以孢粉组合讨论其地质时代古植被与古气候。

PALYNOLOGICAL ASSEMBLAGES OF ZHUXANG FORMATION IN HEFEI BASIN AND ITS GEOLOGICAL AGE, PALEOVEGETATION AND PALEOCLIMATE

The Lower member of Zhuxang formation is characterized by the Pinaceae-Classopol-lis-Cicatricosisporites sporo-pollen zone, which mainly consists of Pinaceae, Classopollis, Cycadopites, Ginkgoretcciina and Bennettitates with a certain amount of Paleopicea of paleopine, Pseudopinus and Caytonipollenites and a few of Psophosphaera, Araucariacites. Spores include Cicatricosisporites, Osmundaciditcs, Gleicheniidites, Cyathidites minor etc.. Its geological age is early Earlier Cretaceous and equals to Hauterivian-Bar-remian period. This palynalogical assemblage represents a vegetational landscape of the forest composed chiefly of Pinaceae, Taxodiaeeae and at that time the climate was warm and moistt.The Upper member of Zhuxang formation is dominanted by the Classopottis-Lygo-diaceae-Glcicheniidites zone. Classopollis is predominanted component in this zone With the great decrease of the Pinaceae pollen and occational pollen grains of Pinaceae of poleopine and quite a few of Cicatricosisporites and Schizaeoisporites, in which also contains a certain amount of Bennettitales, Ginkgoretectina and Cycadopites, and with a little of tricolpate angiospermous pollen. Its geological age is middle Lower Cretaceous and equals to Barremian-Aptian period. It reflects a vegetational landscape of Cheirolepidiaceae, Podozamites and Schizaceae. The climate at that time was a dry tropical-subtropical type.