摘要
经过对青海同仁县古浪堤组实测剖面的17块样品做孢粉分析,在6个层位样品中见有孢粉化石30属41种,据此在该剖面自下而上划分2个孢粉组合:Dictyophyllidites-Di-saccus组合和Verrucosisporites-Di-saccus组合.上述孢粉组合中的孢粉的优势属为Dictyophyllidites,Cyathidites,Verrucosisporites和Chasmatosporites,Protopicea,Pinuspollenites.其中,Dictyophyllidites频繁出现于欧亚、北美、大洋州的晚三叠世和早侏罗世组合,Aratrisporites在南半球大量发育于中三叠世,Asseretospora在澳大利亚的分布时期是中三叠世-早侏罗世.前人于黄南的阿龙江上游及柴陇沟北,古浪堤组产卡尼期的菊石Protrachycerassp.及双壳类Eumorphotis(Asoella)cf.illyrica.综合而言,该地区古浪堤组时代厘定为中-晚三叠世,古植物群生长于暖温带-亚热带河控三角洲环境.
The Triassic Gulangdi formation is well developed in Gulangdi section, Tongren County,Qinghai Province, western China. 17 Palynological samples were collected from the Section; of these, 6 samples are productive. In total, 30 Palynological genera and 41 species have been identified. Based on the stratigraphic distribution, 2 palynological assemblages can be defined in ascending order： Dictyophyllidites-Di-saccus Assemblage and Verrucosisporites-Di-saccus Assemblage. In the two palynological assemblages, the dominant sporopollens matosporites , Protopicea , Pinuspollenites. Among them, are Dictyophyllidites, Cyathidites, Verrucosisporites and Chas Dictyophyllidites is quite common from late Triassic to early Ju rassic in Eurasia, North America, Oceania. Aratrisporites flourished in middle Triassic in southern hemisphere; in Australia, Asseretospora ranged form middle Triassic to early Jurassic. As we know,a late Triassic ammonite fossil Protrachyceras and bivalve fossil Eumorphotis（Asoella）cf. illyrica had been established from the Gulangdi formation at Huangnan County. Based on the above-mentioned ammonite assemblage and the palynological assemblages proposed in this paper, the Gulangdi formation at Gulangdi section may be assigned to middle-late Triassic in age. Furthermore, the palaeoflora in this region may be growing of the environment from warm temperate zone to subtorrid zone.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2007年第5期638-650,共13页
Earth Science-Journal of China University of Geosciences
基金
高等学校全国优秀博士学位论文作者专项资金项目(No200228)
教育部长江学者和创新团队发表计划资助项目(NoPCSIRT0546)
中国地质调查局区域地质调查项目(No200413000007)
关键词
孢粉组合
中-晚三叠世
古浪堤组
青海同仁
palynological assemblage
middle-late Triassic
Gulangdi formation
Tongren County, Qinghai Provice.
