热带海洋学报 ›› 2019, Vol. 38 ›› Issue (6): 51-61.doi: 10.11978/2019010CSTR: 32234.14.2019010

• 海洋生物学 • 上一篇    下一篇

安达曼海浮游有孔虫群落对全新世海洋环境变化的响应

张玲芝1,2, 向荣1(), 唐灵刚1,2, 杨艺萍1, 钟福昌1,2   

  1. 1. 中国科学院边缘海与大洋地质重点实验室(南海海洋研究所), 广东 广州510301
    2. 中国科学院大学, 北京100039;
  • 收稿日期:2019-01-15 修回日期:2019-04-01 出版日期:2019-11-20 发布日期:2019-11-26
  • 通讯作者: 向荣
  • 作者简介:张玲芝(1993—), 女, 江苏省连云港市人, 硕士研究生。E-mail: zhanglingzhi16@mails.ucas.ac.cn
  • 基金资助:
    国家自然科学基金项目(91228207);国家自然科学基金项目(41476040);中国科学院战略专项项目(XDA11030104)

Response of planktonic foraminifera to Holocene marine environmental changes in the Andaman Sea

ZHANG Lingzhi1,2, XIANG Rong1(), TANG Linggang1,2, YANG Yiping1, ZHONG Fuchang1,2   

  1. 1. CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Guangzhou 510301, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-01-15 Revised:2019-04-01 Online:2019-11-20 Published:2019-11-26
  • Contact: Rong XIANG
  • Supported by:
    National Natural Science Foundation of China(91228207);National Natural Science Foundation of China(41476040);Strategic Leading Science & Technology Programme, Chinese Academy of Sciences(XDA11030104)

摘要:

通过对安达曼海重力柱ADM-C1的浮游有孔虫群落分析, 探讨了该区全新世以来的海洋环境演化。研究发现, 该区浮游有孔虫群落总体以热带暖水种Globigerinoides ruber、Globigerinoides sacculifer、Neogloboquadrina dutertreiPulleniatina obliquiloculata等为主。其中G. ruber的相对丰度从早全新世至今呈逐渐降低的趋势, G. sacculifer则呈大致相反的变化趋势。N. dutertrei的相对丰度从11—7.9ka BP较高, 到7.9—3.8ka BP偏低, 3.8ka BP以来又逐渐升高。而P. obliquiloculata的变化趋势则与N. dutertrei大致相反。研究认为, 安达曼海不存在与冲绳海槽类似的晚全新世普林虫低值事件。浮游有孔虫群落Q型因子显示全新世海洋环境呈现三个明显的阶段变化: 早全新世 11—7.9ka BP期间, 浮游有孔虫群落以G. ruber、N. dutertreiG. bulloides为主, 反映了该阶段较强的夏季风降水会导致表层水体盐度较低, 同时冬季风的影响相对较强; 7.9—3.8ka BP期间, 以G. ruber、P. obliquiloculataGlobigerinella aequilateralis为主, 指示水体盐度仍然较低, 同时次表层属种显著增多, 对应了该阶段强盛的印度夏季风, 上层海水混合强烈; 3.8—0ka BP期间, 以G. sacculifer、N. dutertreiP. obliquiloculata为主要特征属种, 而G. ruber相对丰度明显下降, 表明该时期表层海水的盐度有显著上升, 对应了印度夏季风降水的明显减弱。安达曼海浮游有孔虫群落所呈现的全新世海洋环境阶段性变化和陆地夏季风记录有很好的一致性, 也与该孔敏感粒级组分所反映的印度季风的强度变化一致, 表明热带边缘海区的有孔虫群落组合可以很好地响应区域海洋环境变化。

关键词: 全新世, 安达曼海, 浮游有孔虫, 印度季风, 海洋环境

Abstract:

Through analysis of planktonic foraminifera in a gravity core ADM-C1 from the Andaman Sea, the response of planktonic foraminifera to Holocene marine environmental changes in the sea was discussed. The result shows that the planktonic foraminiferal communities in this region are dominated by tropical warm-water species Globigerinoides ruber, Globigerinoides sacculifer, Neogloboquadrina dutertrei, and Pulleniatina obliquiloculata. The relative abundance of G. ruber shows a gradual decreased trend from the early Holocene to present, which is roughly opposite to that of G. sacculifer. The relative abundance of N. dutertrei is higher during 11 to 7.9 ka BP (before present), generally lower during 7.9 to 3.8 ka BP, and then gradually increases after 3.8 ka BP. P. obliquiloculata shows an almost opposite trend to that of N. dutertrei. Our result indicates no obvious Pulleniatina Minimum Eventduring the late Holocene, occurs in the Andaman Sea. Q-mode factor analyses of planktonic foraminifera in the core ADM-C1 identify three stages in marine environmental changes during the Holocene. During the early Holocene (11-7.9 ka BP), planktonic foraminifera assemblage was dominated by G. ruber, N. dutertrei and G. bulloides, which reflected that strong summer monsoon and precipitation led to lower sea surface salinity, while the influence of winter monsoon was also strong during this stage. During 7.9-3.8 ka BP, G. ruber, P. obliquiloculata and Globigerinella aequilateralis dominated, indicating lower sea surface salinity during this period. Meanwhile, there was obviously increase in abundance of subsurface water species, reflecting strong mixing in the upper-ocean waters, possibly due to the strong Indian Ocean summer monsoon at this stage. After 3.8 ka BP, G. sacculifer, N. dutertrei and P. obliquiloculata became the dominant species. The abundance of G. ruber declined obviously, indicating that the salinity of surface sea water significantly increased during this period, which was consistent with the reduced Indian Ocean summer monsoon precipitation. The phase change of the Holocene marine environment reflected by the planktonic foraminiferal assemblages in the Andaman Sea is well consistent with the terrestrial records on the Indian Ocean summer monsoon, and it also shows good consistent with the wind intensity variation in Indian Ocean summer monsoon reflected by sensitive grain size proxy of the same core, suggesting rapid response of planktonic foraminifera to marine environmental changes in the tropical marginal seas.

Key words: Holocene, Andaman Sea, Planktonic foraminifera, Indian Ocean monsoon, Marine environment