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Journal: |
Tectonophysics 2013 No.339
clicks:325 |
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Title:
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Author:
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Guodong Zheng, Sheng Xu, Shouyun Liang, Pilong Shi, Jun Zhao |
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Adress: |
Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, CAS, Lanzhou 730000, PR China |
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Abstract:
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Four gas and six water samples were collected from the Qingzhu River in Qingchuan County, one of the regions affected by the 2008 Ms8.0 giant Wenchuan Earthquake. Gases were discharged soon after the earthquake, but such emissions ceased in October 2008. The predominant gases are CH4, CO2, N2 and O2. The N2, O2 and noble gases are of atmospheric origin. In contrast, the CH4 and CO2 have typical biogenic signatures, with high C1/(C2 + C3), δ13CCH4 (− 56.1 to − 56.6‰); δDCH4 (− 328 to − 345‰); and δ13CCO2(− 6.7 to − 4.9‰). These measurements indicate that the gases are discharged from a shallow reservoir through faults or fractures caused by the earthquake. The discharging gases are significantly distinct from the natural gas fields nearby, suggesting that there are no direct pathways, such as faults or fractures, between the surface and the natural gas reservoir. |
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Comment: |
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