鄂尔多斯盆地中-晚三叠世陆相地层与建阶  

Middle–Late Triassic Terrestrial Strata and Establishment of Stages in the Ordos Basin

作　　者：李亚[1] 姚建新[1] 王思恩[1] 庞其清[2] 

机构地区：[1]中国地质科学院地质研究所,国土资源部地层与古生物重点实验室,北京100037 [2]石家庄经济学院,河北石家庄050031

出　　处：《地球学报》2016年第3期267-276,共10页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目(编号:1212011120142;12120114026701;1212011120115;1212011120116;1211402108021);科技部科技基础性工作专项(编号:2015FY310100);国家重点基础研究发展计划(编号:2011CB403002);国家自然科学基金项目(编号:41472030)联合资助

摘　　要：中生代以来,陆相沉积是中国地层发育特色。海相地层与陆相地层发育特征不同,难以进行对比。三叠纪是中生代第一个纪,在中国发育有众多陆相湖盆。对这些三叠纪湖相沉积开展研究,有助于建立陆相年代地层序列,完成陆相地层划分,赋予可与海相地层对比的年代。我们选择中国北方鄂尔多斯盆地漆水河剖面和窟野河剖面,开展中—上三叠统陆相地层建阶研究。我们在理顺岩石地层划分系统的基础上,分析了各类生物发生、发展以及繁盛的演变历程,划分出生物带及生物界线,并建立了中三叠统印台阶和金锁关阶以及上三叠统杨家坪阶和焦坪阶。印台阶以介形类Tungchuania quadratiformis和Lutkevichinella ansulca的首现层位为底界;金锁关阶以植物Danaeopsis magnifolia,Danaeopsis cf.marantacea和Tongchuanophyllum shensiense的首现层位为底界;杨家坪阶以植物Asterotheca szeiana和Danaeopsis fecunda的首现层位为底界;焦坪阶以植物组合Danaeopsis fecunda-Asterotheca szeiana-Cladophlebis kaoiana首现层位为底界。Terrestrial deposits are especially well developed in the strata of China since the Mosozoic. It is difficult to directly compare terrestrial strata with marine strata because of their different developmental characteristics. In the first period of the Mesozoic period, the Triassic occurred in many terrestrial lacustrine basins of China. The study of these Triassic lacustrine deposits contributes to the establishment of terrestrial chronostratigraphic sequences, the division of the terrestrial strata and the provision of its ages that are comparable with those of marine strata. In this paper, the authors selected the Qishuihe section and Kuyehe section in the Ordos Basin to carry out the study of establishing new stages of Middle-Late Triassic terrestrial strata. The authors first summarized the lithostratigraphic classification of the Ordos Basin, then analyzed the occurrence, development and flourishing of various organisms so as to find out the biological assemblages and biological boundaries, and finally established four new stages： the Middle Triassic Yintaian stage and Jinsuoguanian stage, and the Upper Triassic Yangjiapingian stage and Jiaopingian stage. The bottoms of these stages are respectively defined by the first appearance of the Ostracods Tungchuania quadratiformis and Lutkevichinella ansulca （Yintaian stage）, the plants Danaeopsis magnifolia, Danaeopsis cf. marantacea and Tongchuanophyllum shensiense （Jinsuoguanian stage）, the plants Asterotheca szeiana and Danaeopsis fecunda （Jinsuoguanian stage）, and the plant assemblage Danaeopsis fecunda-Asterotheca szeiana-Cladophlebis kaoiana （Jiaopingian stage）.

关 键 词：鄂尔多斯盆地 陆相地层 中一晚三叠世 阶 

分 类 号：P534.51[天文地球—古生物学与地层学] P539.2[天文地球—地质学]