Spatial relationship between temperature field, hydrothermal alteration and main faults in Shiquan County, Ankang

The fault structure, hydrothermal alteration information and the true surface temperature field are important indicators of geothermal resources. In order to study the spatial distribution of the three, based on the Landsat8 OLI data in Shiquan area, the radiative transfer equation method was used to invert the land surface temperature(LST); and the principal component analysis method was used to extract the hydroxyl hydrothermal alteration information. With the known fault as the center, equally spaced buffer zones on both sides of the fault zone were set up to calculate the average surface temperature and hydrothermal alteration distribution in the buffer zone; the average distance from the center of the fault zone was used as the horizontal axis to plot the relationship among the three. The curve further described the relationship among the true temperature field, the hydrothermal alteration distribution and the main fault structures. The results showed that the NW-trending Lianghe-Chihe fault zone had the highest average temperature in the affected area, with an average temperature ratio of 22.582%, which was similar to the Chengguan-Chihe fault zone and the nearly north-south Lianghe fault. The location of the fault zone was consistent with the surface temperature field. There was a strong correlation between the alteration information; the NW-trending Lianghe-Houliu fault zone and Lianghe-Zengxi fault zone were within the gradient of the average temperature curve. It is speculated that the two sides of the fault zone may have different temperatures field; the fault zone that has a strong control effect on the average temperature and alteration intensity distribution has strong activity; the alteration area ratio at the intersection of the fault zone is 4.263 2%, and the average temperature ratio is 21.178%, reflecting the activity at the intersection of the fault zone is strong.