Variations of opal accumulation rates and paleoproductivity over the past 12 Ma at ODP Site 1143, southern South China Sea  

作　　者：Li Jianru Wang Rujian Li Baohua 

机构地区：[1]Laboratory of Marine Geology,MEO,Tongji University,200092,Shanghai,China [2]Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,210008,Nanjing,China

出　　处：《Chinese Science Bulletin》2002年第7期596-598,共3页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant Nos. 49946011 and 49999560);the Foundation for University Key Teachers, Ministry of Education, China.

摘　　要：The biogenic silica analysis was performed on 463 samples from ODP 184 Site 1143, the southern South China Sea. The results show that the opal content and MAR evidently increased between 12.3 and 5.7 Ma, which was contemporary with the high carbonate and total MARs, reflecting the high biogenic productivity in the late Miocene. This demonstrates the occurrence of the late Miocene 'Biogenic Bloom Event' in the southern South China Sea, corresponding to the late Miocene-early Pliocene 'Biogenic Bloom Event' in the Indian-Pacific Ocean. The increases of opal content and MAR after the middle Pleistocene (about 0.7 Ma) is inferred to result from the enhanced upwelling and nutrient supply, which was induced by the intensified monsoon circulation after the 'Mid-Pleistocene Revolution'.The biogenic silica analysis was performed on 463 samples from ODP 184 Site 1143, the southern South China Sea. The results show that the opal content and MAR evidently increased between 12.3 and 5.7 Ma, which was contemporary with the high carbonate and total MARs, reflecting the high biogenic productivity in the late Miocene. This demonstrates the occurrence of the late Miocene “ Biogenic Bloom Event” in the southern South China Sea, corresponding to the late Miocene-early Pliocene “ Biogenic Bloom Event” in the Indian-Pacific Ocean. The increases of opal content and MAR after the middle Pleistocene (about 0.7 Ma) is inferred to result from the enhanced upwelling and nutrient supply, which was induced by the intensified monsoon circulation after the “ Mid-Pleistocene Revolution”.

关 键 词：OPAL MAR BIOGENIC productivity BIOGENIC BLOOM Event late MIOCENE South China Sea. 

分 类 号：P736[天文地球—海洋地质]