华北平原冀中坳陷东部SFQ1钻孔磁性地层年代学及其地质意义  

Magnetostratigraphic chronology and geology of the SFQ1 borehole, east of Jizhong depression, and its significance to the formation of the North China Plain

作　　者：柳富田[1,2] 杨吉龙[1,2] 陈社明 黄忠峰 陈永胜[1,2] 胡云壮[1,2] 袁海帆 LIU Futian;YANG Jilong;CHEN Sheming;HUANG Zhongfeng;CHEN Yongsheng;HU Yunzhuang;YUAN Haifan(Tianjin Centre,China Geological Survey,Tianjin 300170,Chinas;CGS Key Laboratory of Coast Geo-environment,Tianjin 300170,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局海岸带地质环境重点实验室,天津300170

出　　处：《地质学报》2022年第3期1079-1090,共12页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号41972196);中国地质调查局项目(编号DD20211301,DD20190338,DD20189506)联合资助的成果。

摘　　要：可靠的地层年代标尺对于研究华北平原晚上新世以来沉积物记录的沉积环境演化、新构造运动及古气候演化具有重要意义。本文通过测定冀中坳陷东部的SFQ1钻孔岩芯古地磁,建立高分辨率磁性地层年代框架,并探讨其地质意义。结果表明:SFQ1孔中更新统底界埋深为71.0 m(布容期B/松山期M界线),下更新统底界埋深为197.8 m(松山期M/高斯期Ga界线),上上新统底界埋深在328.7 m(高斯期Ga/吉尔伯特Gi期界线),钻孔底部年龄约为4.74 Ma。不同构造单元钻孔联合剖面揭示,3.6-3.0 Ma期间受青藏高原隆升扩展影响,华北坳陷区被快速充填,至第四纪初地势已变得较为平坦,区域上出现相对水平的等时基准面,现今揭露的第四系底界埋深之所以表现出明显差异,主要是由于第四纪以来新构造运动继承性发展导致的。华北平原晚上新世以来构造运动和沉积结构对水文地质条件产生制约影响,建议在华北平原水文地质调查过程中加强第四系相关研究,以提高水资源评价精度。A reliable chronostratigraphic framework is crucial for better understanding the evolution history of paleoenvironment, neotectonics, and climate change in the North China Plain(NCP). In this study, we established a high-resolution chronostratigraphic framework for the SFQ1 borehole located in the east of Jizhong depression, NCP, and discussed its far-reaching geological significance. In the SFQ1 borehole, the Mid/Lower Pleistocene boundary(0.78 Ma) is placed at 71.0 m depth, the Pliocene/Pleistocene boundary(2.58 Ma) at 197.8 m depth, and the Gilbert/Gauss boundary(3.58 Ma) at 328.7 m depth. The borehole bottom is dated to around 4.74 Ma. Borehole joint sections, across different structural units revealed that the depressions in NCP were rapidly filled up and the NCP had become relatively flat at the beginning of the Quaternary, due to the tectonic uplift effect of the Tibetan Plateau during 3.6-3.0 Ma. Nevertheless, because of the inherited development of neotectonic movement, the study results revealed that the depth of the bottom of the Quaternary shows obvious differences. As the tectonic movement and sedimentary structure of the NCP had a restrictive effect on hydrogeological conditions since late Pliocene, we suggest that Quaternary research should be strengthened during hydrogeological survey in NCP to improve the accuracy of water resources evaluation.

关 键 词：冀中坳陷 磁性地层 沉积结构 新构造运动 华北平原 

分 类 号：P539.3[天文地球—古生物学与地层学] P597.3[天文地球—地质学]