To obtain the uranium-thorium ages of seep carbonates, selected samples were sent to the National Taiwan University. Powder samples were drilled on a class-100 bench in a class-10,000 clean room and then processed in the way following Shen et al. (2003) and (2012). Results were measured with a Thermo-Finnigan Neptune multi-collector inductively coupled plasma mass spectrometer and calibrated by triple-spike (²²⁹Th-²³³U-²³⁶U). The half-lives used for U-Th age calculation are from Cheng et al. (2013).

Yang Lu gratefully acknowledges the support of K. C. Wong Education Foundation and DAAD. U-Th dating was supported by grants from the National Taiwan University (NTU) Core Consortiums Project (112L894202), Higher Education Sprout Project of the Ministry of Education (112L901001).