摘要
海岸带是海陆相互作用的敏感地带,是沿海地区研究第四纪海侵—海退过程的理想场所。基于福建泉州湾沿岸两个第四纪钻孔岩芯(DZ01、DZ02),以地层岩性和岩相组合特征为基础,利用加速器质谱碳同位素(AMS-14C)和光释光(OSL)两种测年方法建立地层年代框架,结合泉州湾现代沉积物具有指相性的地球化学元素含量统计分析结果,运用地球化学元素比值、有孔虫和介形类环境指标判别晚更新世以来的海侵地层,对比区域钻孔资料,探讨了泉州湾MIS 3阶段以来的海侵—海退过程。结果表明:Sr/Ba、Mn/Fe在泉州湾不同水深海相沉积物中变化规律明显,适宜作为泉州湾海岸带海相及海陆过渡相沉积物的指相元素,其界限值分别为Sr/Ba>0.16、Mn/Fe<0.23;泉州湾MIS 3阶段以来发生过两次海侵—海退过程。第一次海侵发生于MIS 3阶段,对应区域上的“福州海侵”,其极盛期发生在距今约35 ka;第二次海侵发生在全新世,对应于区域上的“长乐海进”,其极盛期发生在距今约7~4 ka。研究成果对于重建海岸带沉积环境变化历史、深入认识海陆相互作用及预测未来环境变化具有重要意义。
The coastal zone is sensitive to sea-land interaction,making it an ideal place to study the transgression-regression process in Quaternary coastal areas.Based on the stratigraphic and lithologic characteristics of two Quaternary drill cores(DZ01 and DZ02)in the coastal zone of Quanzhou Bay,Fujian Province,a stratigraphic chronological framework was established by using AMS-14C and OSL dating methods.Combined with the statistical analysis results of geochemical element content of indicating facies in modern sediments in Quanzhou Bay,the geochemical element ratios,foraminifers,and ostracods'environmental indicators were used to identify transgressive strata since the Late Pleistocene.The transgression-regression processes since the MIS 3 in Quanzhou Bay were analyzed by comparing it with the regional borehole data.The results show that the Sr/Ba and Mn/Fe values vary significantly in the marine sediments at different water depths in Quanzhou Bay,making them suitable as indicator elements in the marine and sea-land transitional sediments in the Quanzhou Bay coast,with the limit values of Sr/Ba<0.16 and Mn/Fe<0.23,respectively;there have been two transgression-regression processes since the MIS 3 in Quanzhou Bay.The first transgression occurred in the MIS3,corresponding to the regional"Fuzhou transgression,"which peaked at about 35 ka B.P.The second transgression occurred in the Holocene,corresponding to the regional"Changle transgression,"which peaked at about 7-4 ka B.P.The research results are significant for reconstructing the history of sedimentary environment changes in coastal zones,understanding sea-land interaction,and predicting future environmental changes.
作者
赵红梅
毛欣
刘春雷
李亚松
刘林敬
ZHAO Hongmei;MAO Xin;LIU Chunlei;LI Yasong;LIU Linjing(The Institute of Hydrogeology and Environmental Geology,Shijiazhuang 050061,Hebei,China;Key Laboratory of Quaternary Chronology and Hydro-Environmental Evolution,China Geological Survey,Shijiazhuang 050061,Hebei,China;Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes,Xiamen 361009,Fujian,China)
出处
《地质力学学报》
CSCD
北大核心
2023年第4期569-583,共15页
Journal of Geomechanics
基金
中国地质调查局地质调查项目(DD20190303,DD20221773,DD20221929)
中国地质科学院水文地质环境地质研究所基本科研业务费项目(SK202105,SK202213)。
关键词
泉州湾
海岸带
MIS
3
海侵
地球化学元素比值
沉积环境
Quanzhou Bay
coastal zone
MIS 3
transgression
geochemical element ratio
sedimentary environment
