DISCOVERY OF THE LOWER CRETACEOUS STRATA IN ZHOUKOU BASIN, EASTERN HENAN

The materials dealt with the present paper are obtained from the drilling cores of the Shengqiu Formation in Zhoukou Basin.This formation is composed of a series of grey, dark grey, black claystones and light grey, fine to medium grained sandstones, intercalated with black carbonaceous shales and bands of coal, containing abundant sporo-pollen. This sporo-pollen assemblage is characterized by the predominance of gymnospermous pollen (83-61%), relatively abundant pteridophytic spores (9-17%) and few grains of angiospermous pollen. The gymnospcrmous pollens mainly consist of classopollis (60-84%). In addition, it contains some disacoate pollen grains, Cycadopites,Araucariacites, Psophosphaera,etc.. The pteridophytic spores arc characterized by the dominance of Lygodiaceae(5-12%), which includes Cicatricosisporites, Schi-zaeoisporites, Lygodiumsporites, Concavissimisporites, Klukisporites, Ver-rucosisporitcs, Contignisporites, etc.. Jugella of presumed angiospermous are very rare. This sporo-pollen assemblage is similar to those from South China named Classopollis-Schizaeoisporites microflora (Li wenben, 1980), therefore, the Shenqiu Formation is probably Early Cretaceous in age (Barremian).It is suggested that the climate of Zhoukou Basin should be of dry tropical-subtropical type at that time.