Carbon and oxygen isotope compositions of seep carbonate samples, Dre1, Dre2 and Dre3

To obtain the carbon and oxygen isotope compositions of seep carbonate, samples were ground into powder and send to the Fujian Normal University. About 1 mg powder was reacted with a few droplets of phosphoric acid under 70 °C for two hours. The CO₂ from the carbonate was purified and measured with a Gasbench attached to a Thermo MAT 253 mass spectrometer.