泰国湾T93孔沉积特征：晚更新世以来古温度及东亚冬季风演化记录

发布时间：2018-03-10 00:27

  本文选题：沉积物粒径　切入点：颜色反射率　出处：《国家海洋局第一海洋研究所》2017年硕士论文　论文类型：学位论文

【摘要】：对泰国湾T93沉积物岩心(样长380 cm,水深59 m)的粒度、颜色反射率、磁化率、元素(原位XRF扫描)、不饱和烯酮与GDGTs含量等多个代用指标进行了分析,重建了12.6 ka以来泰国湾古环境的演化历史。研究结果表明,12.6 ka以来泰国湾沉积物组成和沉积相可划分成4个阶段:以红黑色黏土质粉砂为主、缺乏生物壳体的滨海相沉积(12.6-10.7ka),以黏土质粉砂为主的滨海相(10.7-8.2 ka),以粉砂为主的陆架浅海相(8.2 ka~2.5 ka),以粘土为主、沉积环境稳定的浅海相(2.5 ka以来)。U_(37)~k源海水表层温度介于6.1-28.4℃,低温出现在12.6-10.7 ka(可能对应于新仙女木事件),在全新世10.6-8.2 ka期间海水表层温度呈现快速升温的趋势,之后温度趋于稳定。TEX_(86)源海水温度介于19-22.6℃,在12.6-10.7 ka时段呈现高值,与U_(37)~k源海水温度呈现反位相的变化趋势,这可能与TEX_(86)可能指示次表层海水温度有关。敏感粒级组分(6.63~8.63Φ)百分含量变化指示,泰国湾所记录的东亚冬季风强度在12.6-10.7 ka显著增加,这与石笋所记录的东亚夏季风减弱事件相对应;在10.6-8.2 ka,东亚冬季风强度显著减弱,并持续至2.5 ka。全新世以来,沉积记录显示东亚冬季风强度并不稳定。
[Abstract]:The grain size, color reflectivity, magnetic susceptibility, elements (in situ XRF scanning, unsaturated ketenone and GDGTs content) of T93 sediment cores (380 cm in length and 59 m of water depth) in the Gulf of Thailand were analyzed. The evolution history of paleoenvironment in the Gulf of Thailand since 12.6 ka has been reconstructed. The results show that the sediment composition and sedimentary facies of the Gulf of Thailand since 12.6 ka can be divided into four stages: the red and black clay silty sand is the main. Coastal marine sediments lacking biological shells (12.6-10.7 ka), coastal facies mainly silty clay (10.7-8.2 ka), shelf shallow sea facies mainly silt (8.2 ka~2.5 ka), clay dominated, shallow marine facies with stable sedimentary environment (2.5ka) have a surface water temperature of 6.1-28.4 鈩，

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