The sedimentary characteristics of core section from Chencun Village in Pearl River Delta, and their organic carbon isotopic palaeoenvironmental implications
The column section of Chencun drill hole is located in Chencun Village, Foshan, Pearl River Delta. Chronologically, the core was initially deposited at the middle stage of Late Pleistocene and ended in the Late Holocene, as shown by AMS ~(14)C and OSL dating results. Lithostratigraphically, the core, from bottom upwards, experienced successive changes in order of fluvial estuary delta environments. Based on such an essential chronologic and facies framework and further multidisciplinary investigations, including organic carbon isotope, pollen, foraminifera and magnetic susceptibility studies, the authors subdivided the core into the following four stages: (I) Late Pleistocene, 34.15~24.5ka BP, which was fluvial, with mean value of delta ~(13)C_(org) -28.13%oPDB, corresponding to MIS 3, and was characterized by cold slightly wet climate with subtle fluctuations. (II) Late Pleistocene-Early Holocene, 24.5~9ka BP, with was fluvial, with mean value of delta ~(13)C_(org)-29.8%oPDB, corresponding to MIS 2, and was characterized by the conversion of dry- cold climate into warm-dry climate. The YD event was recorded. (III) Early-Middle Holocene, 9~6.7ka BP, which belonged to estuary- delta, with mean value of delta ~(13)C_(org)-27.97 PDB and a small isotopic variation, corresponding to the Holocene Mega Thermal wet hot climate. (IV) Mid-Late Holocene, 6.7~0.44 ka BP, belonged to delta, with mean value of delta ~(13)C_(org)-26.94%o PDB and large amplitude of isotopic changes, and was characterized by remarkable fluctuation from hot-wet through slightly cool to warm-dry climate.