SEISMOLOGY AND GEOLOGY ›› 2022, Vol. 44 ›› Issue (2): 428-447.DOI: 10.3969/j.issn.0253-4967.2022.02.010

• Research paper • Previous Articles     Next Articles


WANG Bo1,2)(), ZHOU Yong-sheng1),*(), ZHONG Jun2), HU Xiao-jing3), ZHANG Xiang3), ZHOU Qing-yun3), LI Xu-mao2)   

  1. 1) State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 10029, China
    2) China Earthquake Networks Center, Beijing 100045, China
    3) Yunnan Earthquake Agency, Kunming 650224, China
  • Received:2021-03-15 Revised:2021-06-07 Online:2022-04-20 Published:2022-06-14
  • Contact: ZHOU Yong-sheng


王博1,2)(), 周永胜1),*(), 钟骏2), 胡小静3), 张翔3), 周青云3), 李旭茂2)   

  1. 1)中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029
    2)中国地震台网中心, 北京 100045
    3)云南省地震局, 昆明 650224
  • 通讯作者: 周永胜
  • 作者简介:王博, 男, 1984年生, 现为中国地震局地质研究所构造地质专业在读博士研究生, 主要研究方向为构造物理实验及流体动力学, 电话: 010-59959322, E-mail:
  • 基金资助:


14 survey lines, with a total of 167 measuring points, were laid out in the northern section of the Red River Fault, the Longpan-Qiaohou Fault, the Heqing-Eryuan Fault, the eastern piedmont fault of Yulong Mountains, and the Lijiang-Jianchuan Fault in the northwest of Yunnan Province, China. Cross-fault soil gas radon, hydrogen, and carbon dioxide have been measured on the above-mentioned faults. The concentration intensity and distribution characteristics of soil gas in the study area were calculated and analyzed. The results show that:
(1)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 7.72ppm to 429ppm, and carbon dioxide are from 0.73% to 4.04%.
(2)The average results of soil gas measurement show that the concentrations of radon are higher than 40kBq/m3 in the sampling sites of Yinjie, Niujie, Gantangzi, while the concentrations of radon in En’nu and Tiger Leaping Gorge measuring lines are smaller; The concentrations of hydrogen are higher than 60ppm in the sampling sites of Yangwang village, Houqing, Dawa, Yangcaoqing and Tiger Leaping Gorge, while the concentrations in Gantangzi and Niujie measuring lines are smaller.
(3)The spatial distribution characteristics of soil gas concentration in faults in northwest Yunnan are obvious, and the intensity of radon and hydrogen concentrations in different active fault zones vary greatly. The intensities of radon and hydrogen concentration are higher and have good consistency in Yinjie and Yangwang village measuring lines located in the northern section of the Red River Fault, the Houqing survey line located in Longpan-Qiaohou Fault, Dawa survey line in the Lijiang-Jianchuan Fault and Yangcaoqing in the south of Chenghai Fault. The soil gas concentration in such sample sites is high and the degassing ability is strong, indicating the different activity characteristics of different segments of the above faults to some extent.
Under the action of tectonic stress, the fault will slip and the rock properties and material structure of the fault will change, thus causing changes of underground material, gas transport channel and transport mode, which is characterized by the change of the concentration and distribution characteristics of escaped soil gas. Combined with the active characteristics of faults, slip rate and geomorphological features, the characteristics of concentration and spatial distribution of two soil gases(radon and hydrogen)are discussed, and the following conclusions are obtained.
(1)There is a large difference in the concentration of escaped soil gas from different faults in the study area, indicating that the content of soil gas is controlled by regional geochemical background values, and there are certain differences in the gas concentration of different sections of the same fault, indicating that the local concentration/flux change is greatly affected by the transport.
(2)The concentration of fault soil gas is related to fault activity, and for different faults, the higher the degree of fault activity is, the higher the concentration of fault gas will be. From the point of fault gas concentration characteristics, the concentrations in the survey lines in the northern section of the Red River Fault and Heqing-Eryuan Fault in the study area vary greatly, suggesting that the fault segmentation is obvious. 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. However, there is no simple linear relationship between the soil gas concentration and the fault slip rate, and it may also depend on its material source, transport channel structure, etc.
(3)The concentration of soil hydrogen at the outcrop of faults(especially normal faults and strike-slip faults)is generally higher, which shows that hydrogen has better indicative significance in revealing the location of fault rupture, and the distribution pattern of soil gas radon concentration is a good indicator for analyzing the characteristics of fault movement.

Key words: northwestern Yunnan Province, soil gas, fault activity, geochemical characteristics


在滇西北地区多条断层进行了跨断层土壤气Rn、 H2、 CO2的浓度测量。测量结果表明, 同一测点断层土壤气浓度随时间没有发生变化, 不同断层的土壤气Rn和H2浓度和分布特征差异较大, 两者浓度范围分别为6.18~168.32kBq/m3、 7.72~429ppm。红河断裂带北段较其他断裂, 气体逸出浓度较高, 显示断层活动性较强。红河断裂带北段和鹤庆-洱源断裂上不同测线的气体浓度差别较大, 显示断裂的分段性明显。土壤氢在断层(尤其是正断层和走滑断层)出露处的浓度一般都较高, 显示了氢气在揭露断层方面具有较好的指示意义, 土壤氡的气体浓度分布特点在分析断层运动特征方面具有较好的指示性。

关键词: 滇西北, 土壤气, 断层活动, 地球化学特征

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