To search and measure the major compositions of seep dolomite, samples were pressed into small particles in ethanol in a mortar and then transferred onto copper grids. Each grid sample was measured with a Thermo Scientific Talos F200S transmission electron microscope at 200 kV in Guangzhou Institute of Geochemistry, Chinese Academy of Sciences.
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).