珠江口伶仃洋ZK1钻孔的磁性地层学研究  

Magnetostratigraphy of Borehole ZK1 in Lingdingyang Bay,Pearl River Estuary

作　　者：曹凯君 任晋珂 李潇濛 吴怀春[3,4] 陈芳 余少华[1,2] 时美楠 甘华阳[1,2] CAO Kaijun;REN Jinke;LI Xiaomeng;WU Huaichun;CHEN Fang;YU Shaohua;SHI Meinan;GAN Huayang(Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou,Guangdong 511458,China;Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou,Guangdong 510075,China;School of Ocean Sciences,China University of Geosciences,Beijing 100083,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing,100083,China)

机构地区：[1]南方海洋科学与工程广东省实验室(广州),广东广州511458 [2]中国地质调查局广州海洋地质调查局,广东广州510075 [3]中国地质大学(北京)海洋学院,北京100083 [4]中国地质大学(北京)生物地质与环境地质国家重点实验室,北京100083

出　　处：《现代地质》2022年第1期58-67,共10页Geoscience

基　　金：南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0209);南方海洋科学与工程广东省实验室(广州)“粤港澳区海洋地质磁学参数和微生物基因测序测试”(72952020120);中国地质调查局“珠江口伶仃洋地区综合地质调查”(DD20190289)。

摘　　要：伶仃洋地区年代格架的建立对区域古环境的重建及海陆交互作用的研究具有重要意义。利用磁性地层学和AMS ^(14)C测年对珠江口伶仃洋ZK1钻孔(113°40′E、22°34′N,孔深100.3 m)0~32 m岩心进行了系统的年代学研究。5个样品的AMS ^(14)C测试年龄为(486±120)~(2268±149)a BP。岩心的岩石磁学测试显示样品的载磁矿物以单畴、多畴的磁铁矿为主。磁性地层学研究显示在取心过程中存在岩心倒置,对岩心倒置深度段的磁性序列进行矫正。将岩心的地磁倾角、强度与东亚地区标准曲线和极光记录相对比,建立了ZK1钻孔岩心(0~32 m)的高分辨率地层年代框架,岩心底界年龄为3.5 ka BP。在该年代格架的控制下,岩心磁学参数具有3~8 a、11 a和21~25 a的周期性变化,推测可能与厄尔尼诺-南方涛动、太平洋十年际涛动和全球地表气温异常周期、太阳活动有关。The establishment of the chronological framework in Lingdingyang Bay(Pearl River Estuary)is of great significance to regional paleoenvironment reconstruction and the study of sea-land interaction.Using magnetic stratigraphy and AMS ^(14)C dating,the geochronology of 0-32 m cores in borehole ZK1(113°40′E,22°34′N,100.3 m depth)in Lingdingyang Bay was analyzed systematically.The AMS ^(14)C ages of the five samples range from(486±120)to(2,268±149)a BP.Rock magnetic analysis of the cores show that the magnetic minerals are mainly single-and multi-domain magnetite.Magnetic stratigraphy demonstrates core inversion in the coring process,and the magnetic sequence of the inverted core depth section is corrected.By comparing the core geomagnetic inclination and intensity with the standard curves and auroral records in East Asia,a high-re-solution stratigraphic age framework of borehole ZK1(0-32 m)is established,with a bottom boundary age of 3.5 ka BP.Under this chronology framework,the core magnetic parameters have periodic changes of 3-8 a,11 a and 21-25 a,which may have been related to the El Nino-Southern Oscillation,Pacific decadal oscillation,global surface temperature anomaly cycles,and solar activity.

关 键 词：珠江口 伶仃洋 磁性地层学 载磁矿物 

分 类 号：P736.2[天文地球—海洋地质] P631.8[天文地球—海洋科学]