| 孟加拉湾MD77190柱状样第3期的韵律沉积记录及快速气候变化 |
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| 引用本文： | 方念乔,丁旋,陈学方,聂浩刚,张世红.孟加拉湾MD77190柱状样第3期的韵律沉积记录及快速气候变化[J].第四纪研究,1999,19(6):511-517. |
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| 作者姓名： | 方念乔 丁旋 陈学方 聂浩刚 张世红 |
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| 作者单位： | 中国地质大学海洋地学研究中心!北京１０００８３ |
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| 基金项目： | 国家自然科学基金!49672135，科技部基础研究 |
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| 摘 要： | 北印度洋孟加拉扇远源区的半远洋沉积记录在氧同位素第２期早期及第３期包含大量高频气候波动信号。该区ＭＤ７７１９０柱状样自第３期起由以富钙质生物壳体和贫钙质生物壳体为主要特色的两类沉积物构成韵律互层,它们的分布状态、互换频率及在生物和化学组分方面的细微变化反映出５９０００～２１０００ａＢ．Ｐ．期间研究区可与Ｈｅｉｎｒｉｃｈ和Ｄａｎｓｇａａｒｄ／Ｏｅｓｃｈｇｅｒ事件遥相对比的气候演化特征。有关的全球热传输机制有待深入探讨。
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| 关 键 词： | 孟加拉湾 氧同位素第3期 韵律沉积 快速气候变化 |
| 收稿时间： | 1999-08-26 |
| 修稿时间： | 1999-09-20 |
RAPID CLIMATIC CHANGE IN OXYGEN ISOTOPE STAGE 3: EVIDENCE FROM THE RHYTHMIC SEDIMENTARY RECORD IN CORE MD77190, BENGAL BAY |
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| Fang Nianqiao, Ding Xuan, Chen Xuefang ,Nie Haogang ,Zhang Shihong.RAPID CLIMATIC CHANGE IN OXYGEN ISOTOPE STAGE 3: EVIDENCE FROM THE RHYTHMIC SEDIMENTARY RECORD IN CORE MD77190, BENGAL BAY[J].Quaternary Sciences,1999,19(6):511-517. |
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| Authors: | Fang Nianqiao Ding Xuan Chen Xuefang Nie Haogang Zhang Shihong |
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| Institution: | Instifitute of Marine Geology and Geophysics, China University of Geoscience, Beijing 100083 |
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| Abstract: | A peculiar rhythmic interbedded sequence consisting of two kinds of deep-seasediments is displayed with Core MD77190 from the distal Bengal Fan （07°41＇ N,87°49＇ E, water depth 3 742m）. One kind of the sediments is rich in planktonicskeletons, opal and organi carbon and another not It is believed that such asequence resulted from allochthocyclic control is of great importance for mirroring theclimatic evolutionary features in the area under study. All sediments consist ofextremely fine terrigenous （< 10μm in general） and coarse bioclastic grains. Singlebeds from 0.5cm to 26cm in thickness can yield information of millennial-scale andeven more detailed variability in paleoclimatology and paleoceanology.According to the distribution and alternation of the different kinds of sedimentsand their variability in micropaleontology and chemistry, tWo phases and fivesubphases can be recognized for oxygen isotope stage 3 and early oxygen isotopestage 2. The most significant turning point lies at 37 000 ～35 000aB. P., dated bycorrelating to SPECMAP and reckoning on average sedimentation rate, which dividesthe rhythmic record into two phases: the low warmer phase （59 000～37 000aB.P.） andthe upper cooler phase （37 000～21 000aB. P.）. The former may be mainly controlledby prevailling SW Indian monsoon while the later influenced to a certain degree byincreasingly strong NE monsoon. The other key points for the regional climatic changeare at 59 000aB.P., 53 000aB.P., 43 000aB.P., 37 000aB.P., 29 000aB.P.and 21 000aB.P.The outlined features in the different subphases are discussed in mis Paper.Most cool and warm episodes detected in the rhythmic sequence can be wellassociated with Heinrich and Dansgaard / Oeschger events found in the greenland icecore and North Atlantic sediment. It is left for future work to find whether or not asensitive heat transfer system exists for the teleconnection over the North Atlantic,Northeast Indian Oceans and other regions. |
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| Keywords: | Bengal Bay oxygen isotope stage 3 rhythmic deposit rapid climatic change |
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