关键词: 滇西北, 土壤气, 断层活动, 地球化学特征

Abstract: Cross-fault soil gas radon, hydrogen, and carbon dioxide have been measured across multiple faults in northwestern Yunnan. The results show that the concentrations and distribution patterns of soil gas radon and hydrogen vary greatly in different faults. The concentrations of radon vary from 6.18Bq/L to 168.32Bq/L, while that of hydrogen are between 7.72×10-6 to 429×10-6. Compared with other faults, the northern section of the Red River fault has a higher concentration of soil gas, indicating that the fault is more active. The escaped gas concentrations of different survey lines on the northern section of the Red River fault and the Heqing-Eryuan fault are quite different, indicating that the fault segmentation is obvious. Soil gas hydrogen has a good role in revealing the location of fault rupture, and soil gas radon distribution pattern was a good indicator in analyzing the characteristics of fault movement.

Key words: Northwest of Yunnan province, soil gas, fault activity, geochemical characteristics