摘要
对四川盆地几条典型的三叠系-侏罗系界线剖面的生物标志、岩性特点、沉积层序及古气候变化进行综合研究,发现Coniopteris属的始现为三叠系-侏罗系界线的古植物标志、双壳类Margaritifera(Qiyangia)的首现和孢粉中孢子与花粉百分含量在界线上、下的显著变化也可作为三叠系-侏罗系界线的生物标志,三叠系-侏罗系界线之上的岩石组合大致可分为4种基本类型:砾岩型、石英砂岩夹砾岩型、石英砂岩型和粉砂质泥岩型。
Based on the synthetical studies of the biological criteria, lithological character,depositional sequence and palaeoclimate of some tapical Triassic-Jurassic boundary sections in the Sichuan Basin, the Tanba section of Hechuan County, Chongqing and the Qilixia section of Xuanhan County are considered respecitively as holostratotype and parastratotype of the non-marine Triassic-Jurassic boundary in this basin. It is suggested that the first appearance of the genus Coniopteris is taken as palaeobotanical mark of the Triassic-Jurassic boundary, while first appearance of the bivalve Margaritifera （Qiyangia） and the remarkable change above and below the Triassic-Jurassic boundary in percent proportion of spores and pollens in sporopollen may be also considered as the biological criteria of this boundary. Meanwhile,it is established that the rock association above the Triassic-Jurassic boundary may be roughly subdivided into four kinds of main types： conglomerate type, quartzose sandstone intercalated with conglomerate type, quartzose sandstone type and silty mudstone type in the Sichuan Basin.
出处
《地层学杂志》
CSCD
北大核心
2005年第B11期565-572,i0002,共9页
Journal of Stratigraphy
基金
国际地质对比计划IGCP506项目成果之一。
关键词
三叠系-侏罗系界线
生物标志
沉积层序
古气候
四川盆地
四川
Triassic-Jurassic boundary, non-marine, biological criteria, depositional sequence, palaeoclimate, Sichuan Basin, Sichuan, Chongqing
