珠江三角洲陈村钻孔剖面沉积特征及有机碳同位素古环境意义  

The sedimentary characteristics of core section from Chencun Village in Pearl River Delta, and their organic carbon isotopic palaeoenvironmental implications

作　　者：赵信文[1] 陈双喜[1] 黄长生[1] 曾敏[1] 陈雯[1] 董好刚[1] 刘凤梅[1] 黎义勇[1] 邵磊[1] 薛永恒 

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205 [2]中国建筑西南勘察设计研究院有限公司,湖北武汉430205

出　　处：《地质通报》2014年第10期1635-1641,共7页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:1212011120174;1212011220012);中国科学院海洋地质与环境重点实验室开放基金项目(编号:MGE2012KG03)

摘　　要：陈村剖面位于佛山市陈村镇。AMS ^14C及OSL测年结果显示，剖面自晚更新世中晚期以来开始沉积，结束于全新世晚期，由老至新经历了河流相-河口湾相-三角洲相沉积环境。根据有机碳同位素曲线变化特征，结合孢粉、有孔虫等鉴定结果及沉积环境综合分析，将剖面划分为4个演化阶段：①晚更新世，34.15-24.5ka BP，属河流相沉积环境，δ^13Corg平均值为-28.13‰，对应MIS 3期冷-稍湿气候，期间小幅波动；②晚更新世-全新世早期，24.5-9ka BP,属河流相沉积环境，δ^13Corg平均值为-29.8‰,对应MIS 2期干冷气候及全新世早期温-干气候，YD事件得以记录；③全新世早-中期，9-6.7ka BP，属于河口湾-三角洲相沉积环境，δ^13Corg平均值为-27.97‰，变化幅度小，对应暖-湿气候；④全新世中-晚期，6.7-0.44ka BP，属于三角洲相沉积环境，δ^13Corg平均值为-26.94‰，变化幅度大，冷暖变化显著，气候特征为热湿-偏凉-暖干。The column section of Chencun drill hole is located in Chencun Village, Foshan, Pearl River Delta. Chronologically, the core was initially deposited at the middle stage of Late Pleistocene and ended in the Late Holocene, as shown by AMS^14C and OSL dating results. Lithostratigraphically, the core, from bottom upwards, experienced successive changes in order of fluvial estuary delta environments. Based on such an essential chronologic and facies framework and further multidisciplinary investigations, including organic carbon isotope, pollen, foraminifera and magnetic susceptibility studies, the authors subdivided the core into the following four stages： （I） Late Pleistocene, 34.15-24.5ka BP, which was fluvial, with mean value of δ^13Corg-28.13‰PDB, corresponding to MIS 3, and was characterized by cold slightly wet climate with subtle fluctuations. （II） Late Pleistocene-Early Holocene, 24.5-9ka BP, with was fluvial, with mean value of δ^13Corg-29.8‰PDB, corresponding to MIS 2, and was characterized by the conversion of dry-cold climate into warm-dry climate. The YD event was recorded. （III） Early-Middle Holocene, 9-6.7ka BP, which belonged to estuary-delta, with mean value of δ^13Corg-27.97‰ PDB and a small isotopic variation, corresponding to the Holocene Mega Thermal wet hot climate. （IV） Mid-Late Holocene, 6.7-0.44 ka BP, belonged to delta, with mean value ofδ^13Corg-26.94‰PDB and large amplitude of isotopic changes, and was characterized by remarkable fluctuation from hot-wet through slightly cool to warm-dry climate.

关 键 词：珠江三角洲 沉积特征 有机碳同位素 古环境变化 

分 类 号：P597.3[天文地球—地球化学] P531[天文地球—地质学]