通过断层气氢探测新郑-太康断裂的浅层位置

Exploration for the Shallow Location of Xinzheng-Taikang Fault via Fault Gas H_2

新郑-太康断裂隐伏于河南省东部平原下,是一条规模较大的北西向断裂带,曾于2010年发生太康4.7级地震,确定该断裂准确的浅层位置对防震减灾具有重要意义。根据深部石油勘探资料,应用德尔格X-am 7000型多气体检测仪,在新郑地区布置2条与断裂走向近垂直的地球化学测线进行土壤氢气浓度测试,结果发现解放路和马庄村-前宫村测线异常点位处氢气浓度分别为背景值的16—33倍和40—50倍。2条H2浓度曲线同步解释出一条倾向变化、宽约150m的走滑断裂带,位置与石油勘探资料吻合良好。此次研究表明利用断层气氢探测隐伏断裂的浅层位置在该区具有较好的可行性。

The Xinzheng-Taikang Fault, striking NW, as a buried fault beneath the eastern plain, is a large-scale fault which induced the earthquake, ML 4.7 in 2010, Taikang county, causing 12 wounded. Confirming the shallow location of the fault is of great significance to seismic hazards defensing. We launched 2 geochemical survey lines across the fault in the Xinzheng area based on the knowledges from Petroleum exploration data, and the outcomes indicated the concentration of H2 at abnormal points in the Jiefang Road survey line is 16-33 times over the background level, while the times of the Mazhuang-Qiangong survey line is 40-50. The two survey lines indicate similar structures of the fault belt, spanning about 150m, and varied inclination and might be filled with fault-clay so as to influence the migration of the gas. More important, the shallow location of the fault from concentration curve of H2 interpretation fits well with that on deep seismic profiles. The research comes out the conclusion that the distribution of the fault gas, H2 is an efficient indicator of the location of buried faults in similar area.