安康石泉县温度场、水热蚀变与主要断裂带空间关系

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

断裂构造、水热蚀变信息与地表真实温度场是地热资源的重要指示标志。为研究三者空间分布关系,基于石泉地区的Landsat8 OLI遥感影像数据,采用辐射传输方程的方法反演地表温度场;并选用主成分分析法提取羟基水热蚀变信息。以已知断裂为中心,向断裂带两侧建立等间距的缓冲区,统计缓冲区内的平均地表温度与蚀变强度;以距断裂带中心平均距离为横轴,绘制三者之间的关系曲线,进一步描述真实温度场、水热蚀变分布与主要断裂构造之间的关系。结果表明,北西走向的两河-池河断裂带影响范围内平均温度最高,平均温度比为22.582%,与城关-池河断裂带和近南北走向的两河断裂相似,断裂带位置与地表温度场和蚀变信息之间存在较强的相关性;北西走向的两河-后柳断裂带、两河-曾溪断裂带处于平均温度曲线梯度变化范围内,推测断裂带两侧可能分属不同的温度场;对平均温度、蚀变强度分布具有较强控制作用的断裂带具有较强的活动性;最多断裂带交汇点处的蚀变面积比为4.263 2%,平均温度比为21.178%,反映了断裂带交汇点处的活动性较强。

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 4.2632%,and the average temperature ratio is 21.178%,reflecting the activity at the intersection of the fault zone is strong.