摘要
长江下游河谷地区拥有丰富的第四纪沉积记录,反映了复杂的古环境变化。利用钻孔地层开展沉积特征研究,对于揭示研究区第四纪沉积环境演化有着重要意义。本研究基于池州地区的6个钻孔资料,综合分析了研究区第四纪沉积相及环境演化过程,提供了全面的第四纪沉积环境变化参考模型。研究表明,该地区经历了新构造活动及复杂的气候变化,在河谷区形成“芜湖组+青弋江组”的地层组合;在丘陵地区形成“下蜀组+戚家矶组”的地层组合。第四纪沉积环境经历了早更新世至中更新世中期温暖湿润气候下的高地残坡积物与冲洪积物堆积阶段;中更新世晚期至晚更新世期间全球气候变化明显,总体趋于寒冷干燥,导致河流活动和沉积特征显著变化;全新世以来,受海平面波动影响,形成了具有不同粒级的沉积物堆积阶段。通过对池州地区第四纪河流相、洪积相、风成相等沉积环境的系统研究,发现该区沉积环境由早更新世温暖湿润阶段向中更新世寒冷干燥转变,中晚更新世期间气候波动频繁,以冷干与暖湿交替旋回为特征,直至全新世的温暖、湿润气候。
The lower Yangtze River Valley preserves abundant Quaternary sedimentary records that offer valuable insights into complex paleoenvironmental changes.Borehole stratigraphy plays a vital role in characterizing these sedimentary sequences and reconstructing the evolution of the Quaternary depositional environment in the region.Drawing upon data from six boreholes in the Chizhou area,this study conducts a comprehensive analysis of Quaternary sedimentary facies and environmental evolution,aiming to establish a reference model for understanding regional Quaternary sedimentary dynamics.The findings suggest that the Chizhou region experienced significant neotectonic activity and climatic fluctuations,which collectively influenced the development of distinct stratigraphic sequences.In the plains,a"Wuhu Formation+Qingyijiang Formation"sequence predominates,while in the hilly areas,the stratigraphy is characterized by the"Xiashu Formation+Qijiaji Formation."During the early to middle Pleistocene,warm and humid climatic conditions favored the formation of high-altitude residual slope deposits and alluvial fan accumulations.In contrast,from the late Middle Pleistocene to the Late Pleistocene,global climatic shifts led to intensified river activity and changes in sedimentary characteristics,with an overall trend toward cooler and drier conditions.The Holocene to the present day is marked by variable sedimentation processes influenced by sea level fluctuations,resulting in the deposition of materials with varying grain sizes.Systematic analysis of fluvial,alluvial,and aeolian facies in the Chizhou area reveals a clear environmental transition:from the warm,humid conditions of the early Pleistocene to the colder,drier environment of the middle Pleistocene.This was followed by frequent alternations between colddry and warm-humid phases during the Late Pleistocene.The Holocene is characterized by a return to relatively stable warm and humid climatic conditions.
作者
张鸿泽
李峰
程捷
贾启超
张攀
刘华国
张彦博
张杰汉
Zhang Hongze;Li Feng;Cheng Jie;Jia Qichao;Zhang Pan;Liu Huaguo;Zhang Yanbo;Zhang Jiehan(School of Earth Sciences and Resources,China University of Geosciences Beijing,Beijing 100083,China;China Earthquake Disaster Prevention Center,Beijing 100029,China)
出处
《震灾防御技术》
北大核心
2025年第2期302-315,共14页
Technology for Earthquake Disaster Prevention
基金
池州市城市活动断层探测及危险性评价项目
中国地震局城市活断层探测与地震危险性评价项目(2150616030203)。
关键词
沉积特征
沉积相
第四纪
环境演化
池州地区
Sedimentary characteristics
Sedimentary facies
Quaternary
Environmental evolution
Chizhou area
