民和盆地早白垩世晚期的孢粉组合

民和盆地的甘肃兰州柴家台地区，下白垩统河口组上亚组含有较丰富的孢粉化石。上亚组上部是以Ｓｃｈｉｚａｅｏｉｓｐｏｒｉｔｅｓ－Ｃｉｃａｔｒｉｃｏｓｉｓｐｏｒｉｔｅｓ为代表的孢粉组合，并可划分出上下两个亚组合，分别以Ｃｌａｓｓｏｐｏｌｌｉｓ－Ｓｃｈｉｚａｅｏｉｓｐｏｒｉｔｅｓ和Ｐｉｃｅａｐｏｌｌｅｎｉｔｅｓ－Ｃｉｃａｔｒｉｃｏｓｉｓｐｏｒｉｔｅｓ来表示。通过对主要孢粉属种地史分布规律的分析和与国内外各地同时代孢粉组合的对比，认为其地质时代是早白垩世晚期的Ａｐｔｉａｎ－Ａｌｂｉａｎ 期，上部的第二亚组合可能更晚，为Ａｌｂｉａｎ 期；孢粉化石产出的这段地层是迄今民和盆地所发现的下白垩统最高的层位

SPORO POLLEN ASSEMBLAGES FROM LATE PHASE OF EARLY CRETACEOUS IN MINHE BASIN

Plenty of sporo pollen fossils were found from the Upper Subformation of Hekou Formation at Chaijiatai, Lanzhou of Gansu, Minhe Basin. The sporo pollen assemblage of the upper stratum of the Upper Subformation was named as Schizaeoisporites Cicatricosisporites. It could be further divided into two subassemblages. The upper one was Classopollis Schizaeoisporites, and the lower one was Piceapollenites Cicatricosisporites. By analysing the periods of the important species and genera in the assemblage and comparing with the known assemblages in various districts, the author cosidered that the geologic age of the assemblage was the late phase of Early Cretaceous (Aptian Albian). The age of the second subassemblage was later which was Albian. So far, the stratum where the sporo pollen fossils assemblage were found was the uppermost one of the Lower Cretaceous that have been found in Minhe Basin.