Spores and pollen from the lower triassic Heshanggou Formation, Shaanxi province, North China

Abstract

Abundant and well-preserved miospores are found in the Heshanggou Formation of the continental Shihchienfeng Group in northeast Shaanxi, North China. A total of 38 species referred to 29 genera are recorded, and 9 new species have been erected. Two species of acritarchs are also recorded. Highly diverse gymnospermous pollen dominate the assemblage which belongs to the Voltziaceaesporites heteromorpha zone of the Early Triassic in North China, which is comparable with those from the late Early Triassic of Western Europe. All evidence supports dating of the Heshanggou Formation as Olenekian in age. The climatic conditions under which the red beds of the Permo-Triassic Shihchienfeng Group accumulated are believed to have been warm and periodically semi-arid. The presence of Eucommiidites and a spinose monocolpate pollen genus in the Early Triassic is noteworthy. The palynological and paleobotanical data do not support the view that the north and south China plates were separated during the Permian.