Application of Stable Oxygen and Carbon Isotope in the Research of Carbonate Diagenetic Environment

Key words: 
• Oxygen and Carbon isotope /
• meteoric diagenetic environment marine buried diagenetic environment /
• buried diagenetic environment /
• shift carbonate rock

Abstract: It is a method which needs to be improved using the component of oxygen and carbon isotope to study and judge the diagenetic environment and the intensity of diagenesis. However, many lab data of samples and the analyzing results of Cambrian and Ordovician in Yichang area，Hu Bei Province;the 110. 3 Ren Well and the NO. 1 Bu Well in Ordos area proved that this method is very effective and practical. The research result indicates that the δ¹⁸O and δ¹³C values shift towards the higher negative values in meteoric diagenetic environment. The δ¹⁸O and δ¹³C values shift towards obviously higher positive values in marine diagenetic environment. The Z value which was calculated using δ¹⁸O and δ¹³C are all more than 122. In buried diagenetic environment, especially deeply buried environment, the 8'80 value shift towards relatively higher negative values. The more the depth, the lower the δ¹⁸O value. However, the δ¹³C value has not changed obviously in the process of burial. All the conclusion above are consistent with the achievement of foreign countries. There are many factors influencing the values of oxygen and carbon isotopes，and the procedures of the buried diagenesis are very complex. So the method metioned above is not absolute. It must be connected with the other research work of petrology and many lab methods.