Radiocarbon Dates in China's Holocene Yangtze Delta: Record of Sediment Storage and Reworking, Not Timing of Deposition

摘要: Evaluation of conventional and AMS radiocarbon dates, obtained for 65 Holocene sediment samples in 20 cores collected the Yangtze delta, China, indicates that only about one 4 dates falls within an expected time range. In this deltaic system, most radiocarbon-dated do not become progressively younger upcore, there is no direct relationship between age depth . About 6 too young, recording locally truncated stratigraphic sections. Of particular note are nearly two-thirds all record ages much old, by 1000 to 10,000 years (23% Pleistocene age). This phenomenon results from introduction old carbon during storage reworking along dispersal path headlands coast. Thus, rather than final deposition at core sites, delta appear indicate a lapse occurred transport cycles fluvial valley plain. There simple, obvious or universal solution radiocarbon-dating problem sequences. The warrants attention since reliable dating sequences essential measurement rates accumulation margin subsidence relative sea level, two parameters needed help implement protection measures vulnerable low-lying At present, multi-method approach (amino acid racemization, isotopic analyses, archaeological determination, others) would constrain age, provide more measure such settings alone.