Summary Abundant and well preserved spores and pollen grains are first recovered from the core samples collected from the uppermost part of the so called Shihhotse Formation of the borehole SR13 near Zhangguizhuang, Tianjin (text fig.1). The sporo pollen assemblage is transitional between those of the Upper Shihhotse Formation and the Sunjiagou Formation. On the one hand, the present assemblage has many common elements with the known assemblages of the Upper Shihhotse Formation (especially its upper part), and the proportion of the pterydophytic spores and gymnospermous pollen (including striate forms) are also comparable, but the index species Microtorispora gigantea and Patellisporites meishanensis etc. of this stage have not been found. On the other hand, the present assemblage is also comparable with those of the known Sunjiagou Formation in composition (Table I). Some Mesophytic or Mesozoic characteristical elements, such as Lueckisporites ? sp., Jugasporites cf. schaubergeroides, Cyasthidites, Dictyophyllidites, Lundbladispora, Apiculatisporis spiniger, Klausipollenites angustus and possibly Classopollis , are present in this assemblage. Based on the detailed disccusion and correlation of the assemblage with the known assemblages, the assemblage is assigned to Late Permian of the three fold division and most probably late Late Permian in age (equivalent to Sunjiagou Formation).
国家自然科学基金 (No .40 0 72 0 0 5 )，中国科学院南京地质古生物研究所创新基金资助