为了准确识别煤田火烧区边界位置,对火烧区磁异常进行更加精细的解释,将张量曲率边界识别方法引入到煤田火烧区磁异常的解释中,探讨分析煤田火烧区磁异常的张量曲率特征.根据煤田火烧区磁异常的特点,利用张量曲率的较大特征值和较小特征值分别圈定煤田火烧区和正常区.模型试验中,通过与常用的Theta 图以及垂向导数等方法对比,体现了张量曲率分析方法在地质体边界识别中的优越性,验证了该方法在火烧区边界识别中的有效性.将该方法应用于乌达某煤田实测磁异常数据的解释,发现利用该方法圈定的火烧区范围和其他勘探结果以及已知地质资料相符,说明该方法可以准确有效地识别煤田火烧区和正常区边界范围,为煤田火烧区的磁异常解释提供很好的依据.
This paper introduces the curvature gradient tensor matrix (CGTM) method to identify the edge of burnt coal areas more accurately and to interpret the magnetic anomaly in more detail. The characteristics of CGTM of the magnetic anomaly in the burnt coal areas are discussed and analyzed. The characteristics indicate that the larger and smaller eigenvalues of CGTM can be used to identify the burnt coal areas and normal areas of the coalfield. In the model tests, the Theta map and vertical derivative edge detection methods were compared with the CGTM. The results demonstrate that the CGTM method is superior in edge detection of geological sources. The effectiveness of the method was also demonstrated. Finally, the method was applied to interpretation of the magnetic anomaly of Wuda coalfield. The results obtained by CGTM method had good agreement with other known geological data. It shows that the method could accurately and effectively identify the edge of coalfield fire areas and normal areas, and is useful for interpreting the magnetic anomaly of coal fire areas.
[1] 朱晓颖, 于长春, 熊盛青, 等. 磁法在煤火探测中的应用[J]. 物探与化 探, 2007, 31(2): 115-119. Zhu Xiaoying, Yu Changchun, Xiong Shengqing, et al. The application of the magnetic method to the detection of under ground coal fires[J]. Geophysical & Geochemical Exploration, 2007, 31(2): 115-119.
[2] 董守华, 李志聃, 邵玉宏. 火烧区烧变岩多边形体△T 人机联作最优 化反演[J]. 煤炭学报, 1996, 21(2): 124-127. Dong Shouhua, Li Zhidan, Shao Yuhong. Interactive inversion method for polygeonal body △T of the burnt rocks in a fire area[J]. Journal of China Coal Society, 1996, 21(2): 124-127.
[3] 陈敏, 邵伟. 应用地面磁法圈定煤田火区边界[J]. 物探与化探, 2010, 34(1): 89-92. Chen Min, Shao Wei. The application of the ground magnetic method to the exploration of fire area boundary of the coal field[J]. Geophysical & Geochemical Exploration, 2010, 34(1): 89-92.
[4] 李曼, 刘天佑. 煤田烧变岩非均匀磁化的二度半模型反演[J]. 煤田地 质与勘探, 2006, 34(2): 67-69. Li Man, Liu Tianyou. Variable magnetization interactive inversion method by 2.5 D for burnt coal[J]. Coal Geology & Exploration, 2006, 34(2): 67-69.
[5] 吴晓瑞, 刘岩波, 高峰. 地面高精度磁测在划定煤田火烧区中的应用[J]. 中州煤炭, 2013(6): 62-64. Wu Xiaorui, Liu Yanbo, Gao Feng. Application of high precision ground magnetic survey in demarcation of burnt coal area[J]. Zhongzhou Coal, 2013(6): 62-64.
[6] 刘大为, 刘天佑, 董建华. 小波多尺度分析在煤田火烧区磁法探测中 的应用[J]. 煤田地质与勘探, 2005, 33(6): 61-63. Liu Dawei, Liu Tianyou, Dong Jianhua. Application of wavelet multiscale analysis in magnetic prospecting of the burnt coal area[J]. Coal Geology & Explaration, 2005, 33(6): 61-63.
[7] Oruç B, Sertcelik I, Kafadar O, et al. Structural interpretation of the Erzurum Basin, eastern Turkey, using curvature gravity gradient tensor and gravity inversion of basement relief[J]. Journal of Applied Geophysics, 2013, 88: 105-113.
[8] Zhou W N, Du X J, Li J Y. The limitation of curvature gravity gradient tensor for edge detection and a method for overcoming it[J]. Journal of Applied Geophysics, 2013, 98: 237-242.
[9] Zhou W N, Li J Y. Semiautomatic interpretation of microgravity data from subsurface cavities using curvature gradient tensor matrix[J]. Near Surface Geophysics, 2014(12), DOI: 10.3997/1873-0604.2014021.
