Calcium carbonate pump during Quaternary glacial cycles in the South China Sea  

作　　者：LIU Zhifei, XU Jian, TIAN Jun & WANG Pinxian Laboratory of Marine Geology, Tongji University, Shanghai 200092, China 

出　　处：《Chinese Science Bulletin》2003年第17期1862-1869,共8页

基　　金：supported by the National Key Basic Research Development Project of China(Grant No.G2000078505);the National Natural Science Foundation of China(Grant Nos.49999560 and 40102010).

摘　　要：The preservation and dissolution of calcium carbonate (namely calcium carbonate pump) controls the pH of seawater in global oceans by its buffer effect, and in turn plays a significant role in global changes in atmospheric CO2 concentration. The results from measured carbonate con-tents over the past 2 Ma at ODP Site 1143 in the South China Sea provide high-resolution records to explore the process of the calcium carbonate pump during Quaternary glacial cy-cles. The results indicate statistically that the highest car-bonate accumulation rate leads the lightest d 18O by about 3.6 ka at transitions from glacials to interglacials, and that the strongest carbonate dissolution lags the lightest d 18O by about 5.6 ka at transitions from interglacials to glacials. The calcium carbonate pump releases CO2 to the atmosphere at the glacial-interglacial transitions, but transports atmos-pheric CO2 to deep sea at the interglacial-glacial transitions. The adjustable function of the calcium carbonate pump for the deep-sea 23CO- concentration directly controls parts of global changes in atmospheric CO2, and contributes the global carbon cycle system during the Quaternary.The preservation and dissolution of calcium carbonate (namely calcium carbonate pump) controls the pH of seawater in global oceans by its buffer effect, and in turn plays a significant role in global changes in atmospheric CO2 concentration. The results from measured carbonate con-tents over the past 2 Ma at ODP Site 1143 in the South China Sea provide high-resolution records to explore the process of the calcium carbonate pump during Quaternary glacial cy-cles. The results indicate statistically that the highest car-bonate accumulation rate leads the lightest d 18O by about 3.6 ka at transitions from glacials to interglacials, and that the strongest carbonate dissolution lags the lightest d 18O by about 5.6 ka at transitions from interglacials to glacials. The calcium carbonate pump releases CO2 to the atmosphere at the glacial-interglacial transitions, but transports atmos-pheric CO2 to deep sea at the interglacial-glacial transitions. The adjustable function of the calcium carbonate pump for the deep-sea 23CO- concentration directly controls parts of global changes in atmospheric CO2, and contributes the global carbon cycle system during the Quaternary.

关 键 词：中国 南海 碳酸钙 第四纪 冰川旋回 海洋钻探图 古气候 

分 类 号：P595[天文地球—地球化学]