DISCUSSION ABOUT THE RELATIONSHIP BETWEEN KALIUM AND ARGON IN RESEARCH OF GAS AND SOURCE ROCK CORRELATION OF NATURAL GAS
K-Ar关系在天然气气源对比研究中的应用

Based on the radioactivity of Kalium which generates 40 Ar in source rock through radioactive decay with geologic time passing by, the age accumulation effect of Argon isotope in natural gas pool is founded. For the natural gas from the crust, 40 Ar mainly derives from Kalium-Crust trapping of 40 K. As the age of sourcerock becomes old, the content of the radioactive 40 Ar increases, the 40 Ar/ 36 Ar ratio also increases. The article carries out researches on the two basins--Tarim basin and Ordos basin by using the relationship between Argon isotope in!natural gas and the generatrix Kalium in different types of source rocks. After the collection and collation of K~2O content as much as possible in different types of source rocks, for the three types of source rocks--clastic rocks, ingredient rocks and carbonate rocks, it can be discovered that the change of Kalium content mainly rests upon the content of the clay minerals in source rocks. The difference of K~2O content in rocks is about the magnitude of 10. Research on the relationship between Kalium and Argon is very valuable to the gas and source rock correlation in petroliferous basins which have different types of source rocks.