珠江三角洲PD孔沉积物的碳氮记录及其环境意义  

CARBON-NITROGEN RECORD IN SEDIMENTS OF CORE PD IN THE PEARL RIVER DELTA AND THE ENVIRONMENTAL SIGNIFICANCE

作　　者：高芳蕾[1] 杨小强[1] 董艺辛[1] 梁秋花 周文娟[1] 

机构地区：[1]中山大学地球科学系,广州510275 [2]深圳市勘察测绘院有限公司,深圳518028

出　　处：《海洋地质与第四纪地质》2006年第2期33-39,共7页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40104002);广东省自然科学基金项目

摘　　要：对位于广州番禺东涌镇PD孔的三角洲沉积物进行了有机碳、陆源有机碳和碳氮比值分析，结合微体古生物和^14C年代资料，将岩心划分为4个阶段：阶段Ⅰ（23．88～21．71kaBP）有机碳、陆源有机碳含量递增，存在大量有孔虫和介形虫，反映海侵作用逐渐减弱；阶段Ⅱ（21.71～3．79kaBP）是一层花斑黏土，有机质含量极低，指示风化作用强烈；阶段Ⅲ（3．79～2．88kaBP）碳氮比值、陆源和内源有机碳比值的变化在平衡状态波动，指示海平面上升的海陆过渡环境}阶段Ⅳ（2．88kaBP以来）陆源有机碳比重和碳氮比值较高，主要为受河流作用控制的陆相沉积，气候温暖湿润，陆源碎屑丰富。Organic carbon, allochthonous organic carbon and C/N ratio, together with microfaunal and radio carbon dating results of the delta sediments in core PD in the Pearl River delta area are investigated to determine environmental changes. Four stages can be recognized since late Pleistocene. The first stage（about 23.88-21.71 kaBP） is characterized by gradually increasing organic carbon and allochthonous organic carbon, with plenty of foraminifers and ostracods, which indicates the weakening of sea-level rising. The second stage（about 21.71～3.79 kaBP） is represented by a layer of multi-color clay with extraordinary low organic matter, which implies strong weathering. In the third stage（about 3.79～2.88 kahP）, C/N ratio, allochthonous and autochthonous organic carbon ratio fluctuate according to the balance state, which means a marine terrestrial transitional environment. In the fourth stage（about 2.88 kaBP-present）, higher allochthonous organic carbon proportion and C/N ratio reflect terrigenous facies mainly controlled by fluvial effect,and the warm and humid climate brings rich allochthonous clastic matter.

关 键 词：有机碳 陆源有机碳 碳氮记录 晚更新世 珠江三角洲 

分 类 号：P736.2[天文地球—海洋地质]