Study On Application Of Geogas Detection Fault Zone

Our country is affected by the fault activity, its distribution scope is wide, the frequency is high, and the occurrence intensity is big. Fault activity can cause earthquakes, landslide, rock collapse, crack and other disasters. And the earthquake and other disaster activities will also have a greater effect on the fault activity, making the corresponding reflection of the fault. The research on active fault can deepen the understanding of this kind of geological disaster, and it has important practical significance and scientific research value in the field of earthquake resistance and disaster reduction. Active fault is the main channel for the upward migration of the deep upward flow. The corresponding exception embodied in the fault zone at the top of the updraft relative enrichment, showed exceptionally strong, rising air carried by radon, the elements in geogas. The existence, distribution and activity of the active faults can be indicated by the measurement of the rising air flow. It can provide great convenience for the later exploration work and has the leading meaning. Maoxian is located in the back range faults of Longmen orogenic mountain, is an earthquake prone areas. It is a frequent and intense area of fault activity. It is an important area of active faults, has important significance to research and application of soil radon measurement, gas measurement.This study is on the basis of previous work, with using the research methods of geogas measurement, soil radon measurement, soil geochemical measurement of vertical profile. So the study of soil, soil radon and the elements in geogas in the active fault zone obtained further understanding. With the correlation between the anomalies characteristics of soil radon and gas elements and fault zone in the spatial scale, this research studys on the indication function of radon measurement and the geogas measurement on the fault zone. Comparison of the indicating effect of soil radon measurement and geogas measurement on the fault, the further study on the geochemical characteristics of the fault zone selects geogas method. Through a variety of research methods to the study of the region, to further understand:(1) In the study area fracture with the overlying soil properties of uniform and stable. The plants in the study area are few, and the content of organic matter in the soil is low. The reaction degree of soil and gas components is low, and it is less influence of geogas measurement. The soil environment is a stable gas measurement environment.(2) The soil radon measurement results show that the radon anomalies are well correlated with the fault zone. It indicates the distribution of the fault zone, the silica layer and the part of the fissure. But in the study area, the radon anomaly is affected by the soil cover, and partial anomalies are not obvious or occur an offset.(3) According to the anomaly position and shape of the elements in geogas content curve,the characteristics of multi element anomaly are similar, such as Sr, Mn, Cu, Cd, Sn, Sb, etc.. The anomalies are above the fault zone, well correlated with the fault zone. They are more accurate to indicate the distribution and the relative activity of the active fault. At the same time, the geogas anomalies are less affected by soil cover.(4) Radon measurement is high sensitivity, strong real-time, but it is easy to be influenced by external factors. It is only a measure of radon, therefore, the consistency of the instrument must be good and the stability of it should be high. Geogas measurement is a simple and convenient method of measuring, and the sampling device has good consistency and high stability. The fault zone can be indicated by the method of multi element anomalies. This is more stable and reliable, with high reliability.