[1]LIU Jie,LI Ying,CHEN Zhi,et al.Geochemical Characteristics and Genesis of Soil Gas CO2 in the Longxian-Baoji Fault Zone[J].Journal of Seismological Research,2022,45(02):217-228.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0020
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
45
Number of periods:
2022 02
Page number:
217-228
Column:
Public date:
2022-05-20
- Title:
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Geochemical Characteristics and Genesis of Soil Gas CO2 in the Longxian-Baoji Fault Zone
- Author(s):
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LIU Jie1; LI Ying2; CHEN Zhi2; WANG Xin1; ZHAO Xiaomao1; FENG Xijie1; WANG Jingli1
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(1.Shaanxi Earthquake Agency,Xi'an 710068,Shaanxi,China)(2.Institute of Earthquake Forecasting and Key Laboratory of Earthquake Prediction,China Earthquake Administration,Beijing 100036,China)
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- Keywords:
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soil gas CO2; intensity of gas activity; stable carbon isotope; fault activity
- CLC:
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P315.724
- DOI:
-
10.20015/j.cnki.ISSN1000-0666.2022.0020
- Abstract:
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The Longxian-Baoji Fault Zone is located in the northeast edge of the Qinghai-Tibet Block and belongs to the southernmost segment of the arc fault belt in the southwest edge of the Ordos Block.To compare the activity of the Qishan-Mazhao Fault in the south of the Longxian-Baoji Fault Zone with the activty of the Guguan-Guozhen Fault in the north,we study the geochemical features of the soil gas CO2 in the faults.Six survey profiles for surveying CO2 are deployed across the two faults and two periods of observation are carried out.We obtain 150 observed values of CO2 component concentrations.In addition,we collect 60 CO2 samples for stable carbon isotopic composition measurements.We find that the intensity(1.56-2.70)of CO2 activity in the Qishan-Mazhao Fault is greater than that(1.73-1.75)in the Guguan-Guozhen Fault.And the source of the CO2 in the Qishan-Mazhao Fault is closer to the end member of the deep materials.This suggests that the connectivity of the underground structures of the Qishan-Mazhao Fault is better and the fault's locking degree is lower.Meanwhile,the gas activity in the Guguan-Guozhen Fault is weaker and the fault's locking degree is higher.Thus,the earthquake risk in this fault zone is higher.