ESR CHRONOLOGY OF WELL QC_2 IN TBE SOUTH YELLOW SEA
Ye Yuguang Diao Shaobo He Jie(Institute of Marine Geology,MGMR,Qingdao,266071,China)Gao Juncheng(National Institute of Metrology,Beijing,100013,China)
Well QC_2(34°18'N, 122°16'E)is located on the offshore slope in the northeast of thePleistocene Yangtze Rive delta and to the east of the ancient Yellow River delta. The av-erage recovery from QC_2 is up to 90.4%,and the core nearly reaches the top boundary ofOlduvai subchron. For Quaternary studies,QC_2 is one of the best wells in China with ob-vious geologic settings.The ages of 33 samples which were taken from QC_2 in the South Yellow Sea weredetermined by ESR method.The correlation of ESR ages with ￣(14)C ages,microbios-tratigraphy and magnetostratigraphy,shows a correspondence with the horizons and alsowith the geological backgrounds.The ESR ages build a more complete chronology,andthe maximum ESR age is 1.9Ma.Reliable ESR ages of sediments within several hundredthousand years can be obtained from Ge centres of quartz in sediments,while the ESRages of older sediments(more than 5 ×10￣5 a)can be obtained from E'centres of quartzin marine conditions by using a higher microwave power.