摘要
本文通过对长江三角洲北翼东台地区ZKA02孔岩石地层、磁性地层、生物地层和年代学数据的分析研究,结合区内其他钻孔的对比,确定了该孔第四纪年代地层序列。结果表明:该孔第四系底界埋深297.36 m,地质年龄为2.58 Ma,置于松山/高斯极性时(M/G)分界处;中、下更新统界线埋深168.97 m,与布容/松山极性时界线(B/M)吻合,时代为0.78 Ma;中、上更新统界线埋深98.90 m,上更新统底部与本钻孔MIS5底部大致相当,时代为120 ka BP;上更新统与全新统界线埋深11.08m,年龄约为12kaBP,深海氧同位素I阶段(MIS1)与末次盛冰期(LGM)界面为全新统底界。本孔的微体古生物分析进一步揭示了3层海相沉积层,分别对应MIS5(74—128 ka)、MIS3(24—60 ka)、MIS1(现在—12ka)。该结果较好地印证了中国东部沿海地区晚更新世以来发育的3次大规模海侵事件,同时也为本地区晚更新世以来的地层划分提供了必要的数据支撑。
Borehole ZKA02 is located in Dongtai City,Jiangsu Province,the north wing of the Yangtze River Delta.Based on lithostratigraphic,biostratigraphic,magnetostratigraphic and chronostratigraphic study of the core sediments,the authors established its Quaternary chronological framework:The lower boundary of Quaternary,consistent with the geomagnetic boundary of Matuyama/Gauss(M/G)at 2.58 Ma,was found at 297.36 m in depth.The Early/Middle Pleistocene boundary,in accord with the geomagnetic boundary of Brunhes/Matuyama(B/M)at 0.78 Ma,was found at 168.97 m.The Middle/Late Pleistocene boundary was consistent with the end of MIS5 at 120 ka BP,was found at the depth of 98.90 m.The Late Pleistocene/Holocene boundary is 11.08 m,about 12 ka BP.The micropaleontological analysis of this hole further revealed three marine sedimentary layers,corresponding to MIS5(74–128 ka),MIS3(24–60 ka)and MIS1(now–12 ka).The results are also better confirmed the three large-scale transgressive events developed in the eastern coastal area of China since the Late Pleistocene,and also provides necessary data support for the stratigraphic classification of this region since the Late Pleistocene.
作者
刘宪光
杨晋炜
胡利
夏斌
孙丰瑞
王钜
董军林
LIU Xian Guang;YANG Jin Wei;HU Li;XIA Bin;SUN Feng Rui;WANG Ju;DONG Jun Lin(Institute of Geochemical Exploration and Marine Geological Surrey,East China Mineral Exploration and Development Bureau for Non-ferrous Metals,Nanjing 210007;Key Laboratory of Coastal Salt Marsh Ecosystems and Resources,Ministry of Natural Resources,Nanjing 210007;Central South Geological Survey Institute of China Metallurgical Geology Bureau,Wuhan 430300)
出处
《地层学杂志》
CSCD
北大核心
2023年第1期49-58,共10页
Journal of Stratigraphy
基金
中国地质调查局(1212011220539)资助。
关键词
长江三角洲
第四纪
微体古生物
古地磁
海侵层
Yangtze River Delta
Quaternary
micropaleontology
paleomagnetism
transgressive layer
