摘要
经过野外填图和追索不整合面,在贵阳地区的三叠纪碳酸盐岩台地—盆地过渡带上识别出4个不整合界限地层单位(或“层序”),它们与哈克等人(1988)的三叠纪全球海面变化旋回表基本上可以对比。根据岩相和地层结构分析,进一步细分出:海侵的碳酸盐岩缓坡,高水位的镶边碳酸盐岩台地,低水位的碳酸盐岩斜坡和盆地碎屑岩—碳酸盐岩混合等四类沉积体系。有证据表明,海侵面是盆地地层序列内的重要沉积间断面,因此提议最好以陆上暴露带不整合—海侵面,作为不整合界限地层单位(“层序”)的界面。
Through field mapping and tracing of unconformities, four unconformitybounded stratigraphic units (or 'sequences') have been recognized in the Triassic carbonate platform-basin transition zone of the Guiyang area, Guizhou Province. They may be essentially correlated with the table of the cycle of the Triassic global sea-level changes presented by Harke et al. (1988). On the basis of an analysis of lithofacies and stratigraphic structure, four sedimentary systems may be distinguished; they are the marine transgressive carbonate rock gentle slope, high-water level carbonate rock platform, low-water level carbonate rock slope and basinal clastie-carbonate rock mixture. Thus the features of the Triassic stratigraphic framework in the Guiyang area has been ascertained. The transgression surfaces represent important depositional breaks in the basin sequences. Therefore the author proposes that it is advisable to take the unconformity-transgression surface in the subaerial exposure zone as the interface of the unconformity-bounded stratigraphic units ('sequences'). More intensive biostratigraphic and chronostratigraphic studies should be made in the future.
出处
《中国区域地质》
CSCD
1993年第2期97-106,T002,共11页
Regional Geology of China
