A broad deglacial δ^(13)C minimum event in planktonic foraminiferal records in the Okinawa Trough  

作　　者：LI Tiegang, LIU Zhenxia, M. A. Hall, Y. Saito, S. Berne, GANG Shuxi & CHENG ZhenboInstitute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China The First Institute of Oceanography, State Oceanic Administration, Qingdao 266003, China Godwin I 

出　　处：《Chinese Science Bulletin》2002年第7期599-603,共5页

基　　金：This work was supported jointly by SSTC andSOA, China and IFREMER, France and also by the National Natural Science Foundation of China (Grant Nos. 49736210 and 40176019);the National Major Basic Research and Development Project (Grant No. G20000467)

摘　　要：The equatorial Pacific upwelling zone has been suspected of playing an important role in the global atmospheric CO2 changes associated with glacial-interglacial cycles. In order to assess the influencing scope of the surface water deglacial δ13C minimum in the tropical low-latitude Pacific, the core DGKS9603, collected from the middle Okinawa Trough, was examined for δ13C records of planktonic fo-raminifera N. dutertrei and G. ruber. The planktonic fo-raminiferal δ13C records show a clear decreasing event from 20 to 6 cal. kaBP., which is characterized by long duration of about 14 ka and amplitude shift of 0.4×10-3. Its minimum value occurred at 15.7 cal kaBP. The event shows fairly synchrony with the surface water deglacial δ13C minimum identified in the tropical Pacific and its marginal seas. Because there is no evidence in planktonic foraminiferal fauna and δ18O records for upwelling and river runoff enhancement, the broad deglacial δ13C minimum event in planktonic foraminiferal recordsThe equatorial Pacific upwelling zone has been suspected of playing an important role in the global atmospheric CO2 changes associated with glacial-interglacial cycles. In order to assess the influencing scope of the surface water deglacial δ13C minimum in the tropical low-latitude Pacific, the core DGKS9603, collected from the middle Okinawa Trough, was examined for δ13C records of planktonic fo-raminifera N, dutertrei and G. ruber. The planktonic fo-raminiferal δ13C records show a clear decreasing event from 20 to 6 cal. kaBP., which is characterized by long duration of about 14 ka and amplitude shift of 0.4 × 10-3. Its minimum value occurred at 15.7 cal kaBP. The event shows fairly synchrony with the surface water deglacial δ13C minimum identified in the tropical Pacific and its marginal seas. Because there is no evidence in planktonic foraminiferal fauna and δ18O records for upwelling and river runoff enhancement, the broad deglacial δ13C minimum event in planktonic foraminiferal records revealed in core DGKS9603 might have been the direct influencing result of the deglacial surface water of the tropical Pacific. The identification for the event in the Okinawa Trough provides new evidence that the water evolution in the tropical low-latitude Pacific plays a key role in large regional, even global carbon cycle.

关 键 词：PLANKTONIC foraminiferal δ13C minimum EVENT Oki-nawa TROUGH last deglaciation. 

分 类 号：Q178[生物学—水生生物学]