孟加拉湾深海记录中的等深流活动特征及其环境意义初探  

Contour Currents in Deep-Water Records from Bay of Bengal and Its Environmental Implication

作　　者：方念乔[1] 陈萍[1] 吴琳[1] 石峰[1] 

机构地区：[1]中国地质大学海洋地学研究中心,北京100083

出　　处：《地球科学（中国地质大学学报）》2002年第5期570-575,共6页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金主任基金 (No .4 0 170 6 14 );国家"973"项目 (G2 0 0 0 0 4 6 70 5)

摘　　要：实地观测和对沉积记录的研究表明 ,孟加拉湾存在强大的等深流活动 .通过采自孟加拉深海扇东部和中部的 3支活塞岩心的沉积学研究表明 ,那些氧化色彩强烈、钙质生物壳体溶蚀严重、不存在粒序层理的粉砂质薄层实际上是等深积作用的产物 .源自两极的等深流是全球温盐循环系统的关键组分 ,它们在过去 15 0ka的历史中曾经多次得到强化 ,不仅对研究区的环境变化产生重要影响 ,而且可能作为纽带 ,加强了低纬地区与极区在气候意义上的遥相关 .等深流的强化与冰川旋回之间似乎不存在密切关联 ,氧同位素第 3 ,4,5期内均可发现明显的强化记录 .关于强化的控制机制有待深入探讨 .The analysis of measured data and sedimentary records shows that strong contour currents occur in the Bay of Bengal. The sedimentary research into 3 piston cores from the middle and eastern Bengal deep water fan indicates those thin bedded muddy silts, with heavy oxidation colors and a few calcareous gravely corroded shells but free of any graded bedding, are products of deposition of reworked materials by geostrophic bottom currents. The contour currents derived from the Arctic and Antarctic, essential constituents of the global thermohaline circulation, were repeatedly enhanced in the past 150 ka. This intensification of the currents, presenting a great impact on the environment changes in the province under study, may serve as a link to make a climatic enhancement of the tele connection between the low latitude and the pole regions. It is very unlikely that there is a close relation between the intensifications of the contour currents and the glacial cycles. The records of intensified contour currents can be observed in oxygen isotope stages 3, 4 and 5. The enhanced controlling mechanism remains to be further investigated.

关 键 词：深海记录 等深流 孟加拉湾 识别标志 温盐循环 古环境 等沉积作用 

分 类 号：P736.22[天文地球—海洋地质]