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文章对位于长江三角洲南翼平原区西部的SZ04孔进行了详细的磁性地层学研究。结合绝对测年,并与标准极性柱对比认为269.2 m岩芯清楚的记录了布容(Brunhes)、松山(Matuyama)、高斯(Gauss)极性带,及贾拉米洛(Jaramillo)、奥尔都维(Olduvai)等亚极性带和布莱克(Black)地磁漂移,其中B/M、M/G界限深度分别为100 m和155 m;SZ04孔底部碎屑沉积物形成的年龄大于5.23 Ma。研究发现,钻孔沉积物磁化率、岩石地层特征在特殊的时代界限附近有明显变化可进行区域对比。分析表明,第四纪以来长江三角洲地区一直存在持续的构造沉降,且沉降中心持续往南东方向移动,构造沉降运动的发生和发展存在三个重要的期次分别为2.58 Ma,0.78 Ma和0.125 Ma。
The paper carried out a detailed magnetic stratigraphy study on SZ04 hole located in the western part of the plains of the southern Yangtze Delta. Combined with the absolute dating and comparison with the standard polar column, it is considered that the 269.2 m core clearly recorded Brunhes, Matuyama, Gauss polar bands, and Jaramillo, Olduvai and Black geomagnetic drift, with B / M and M / G demarcation depths of 100 m and 155 m, respectively. The age of the sediments formed at the bottom of SZ04 is greater than 5.23 Ma . The study found that the magnetic susceptibility of drilling sediments, rock stratigraphy characteristics in the vicinity of the special times have obvious changes in the region can be compared. The analysis shows that there has been continuous structural subsidence in the Yangtze River Delta since Quaternary, and the center of subsidence has continued to move to the south and east. There are three important periods of occurrence and development of structural subsidence: 2.58 Ma, 0.78 Ma and 0.125 Ma.