Where the river turns old: urbanized deltas imprint a fossil signature on black carbon exported to the ocean

X Xin Yi (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) X Xiaofei Geng G Guangcai Zhong B Bolong Zhang S Sanyuan Zhu (State Key Laboratory of Advanced Environmental Technology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences) H Hongxing Jiang Y Yangzhi Mo C Chuxin Yao S Shizhen Zhao J Jun Li H Huizheng Che G Gan Zhang