关键词: 第四纪地层, 光释光测年, 磁性地层学, 海相地层, 年代地层剖面

Abstract: Based on the optical dating and paleomagnetic testing results,we make a chronostratigraphic research of Huanghua depression and Cangxian uplift which are two tectonic units of Tianjin area.In this paper,we establish a Quaternary stratigraphic section and make a new division of the Quaternary strata.The result shows that the two tectonic units have similar sedimentation histories,but many differences exist.On the one hand,both units have received transgression since the Quaternary and some marine strata formed to various extents,which indicates different transgression sedimentation histories between them;on the other hand,the Quaternary stratigraphic sequences of the two units are greatly different,indicating different sedimentation histories,and consequently,the type and thickness of sediments are obviously different,so they belong to different sedimentary units.The study also shows the depths of bottom interfaces of Holocene,upper Pleistocene and middle Pleistocene as 19m,45m and 103m,respectively in hole BZ1 in Huanghua depression and 13m,30m and 56m respectively in hole BZ2 and hole TN3 in Cangxian uplift.The depth of bottom interface of the Quaternary is about 162m,much smaller than the result of the previous Quaternary strata division.

Key words: Quaternary strata, OSL dating, magnetostratigraphy, marine strata, chronostratigraphic section