珠江口SX97孔7000aB.P.的气候环境变化及流域响应  

Core SX97:Climatic and Environmental Changes Since 7?000 a B.P. and Drainage Responses

作　　者：周厚云[1] 余素华[1] 郭国章[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640

出　　处：《地理科学》2001年第4期368-372,共5页Scientia Geographica Sinica

基　　金：国家自然科学基金 (编号 49672 13 8)

摘　　要：综合考虑矿物、元素地球化学和孢粉等多方面的资料 ,对珠江口北岸SX97孔揭示的 70 0 0aB .P .以来的气候环境演化提出了一种 5阶段划分方案 ,这种阶段性在SX97孔的各项指标上均有很好的对应 ,也与华南地区基于海岸沙丘、海滩岩和海相沉积地层等的早期研究成果能较好地对应。在此基础上 ,初步探讨了气候环境变化中的流域响应 ,发现SX97孔揭示出气候环境变化中有很好的流域响应。如当气候环境偏湿偏热时 ,流域风化作用更加强烈 ,有更多的铁元素流失 ,同时流域植被更发育 ,对降水有更好的缓冲作用 ,导致河口沉积物中含有更多的铁元素(包括二价铁和三价铁 )、更少石英矿物和更多粘土矿物。Based on a multi proxies study (including mineralogy, elemental geochemistry and pollen analyses) on Core SX97, which lies on the north flank of the Pearl River estuary, the authors suggest that the climatic and environmental evolution since 7000 a B.P. over the Pearl River Delta area could be divided into five stages. These stages between different climatic and environmental proxies, such as mineralogy, elemental geochemistry and pollen data, correlate very well with each other as well as with the climatic and environmental information over the coastal zone of South China that was recovered previously from the coastal dunes, beach rocks and marine deposits. Then, the drainage response of the Pearl River to local climatic and environmental variations is explored. Core SX97 shows that the Pearl River drainage response sensitively to local climatic and environmental changes. When the climate over the Pearl River drainage was relatively warm and humid, weathering was relatively strong, relatively more iron was lost from the weathering profile, and better vegetation was developed over the drainage. All these would result in more FeO and Fe 2O 3, less herbal relative content, less quartz and more clay mineral (such as kaolinite, montmorillonite and illite) mass fractions in the estuary sediments. Contrary to this was the situation when the climate was relatively cold and arid.

关 键 词：珠江口 SX97孔 7000aB.P. 气候环境变化 流域响应 元素地球化学 孢粉 粘土矿物 

分 类 号：P532[天文地球—古生物学与地层学]