Abstract: Accurate delineation of the coal thinning zone caused by igneous rock intrusion, is beneficial to the high yield and high efficiency for the mechanized coal mining face. The igneous rock intrusion has been detected by the radio wave perspective on one coal face. The initial amplitude and the absorption coefficient have been got by comprehensive curves analysis to reconstruct the absolute attenuation tomography. The absorption coefficient β can denote the exceptional response features. The contrast between tomography results and the actual coal seam thickness shows that: 1) The anomaly of coal thinning zone caused by igneous intrusion is obvious in absolute attenuation tomography map. Its distribution range conforms very closely to the perspective anomaly area, and radio wave perspective to detect the coal thinning zone is feasible. 2) The absorption coefficient β is corresponding to the igneous rock erosion thickness. According to the difference between abnormal absorption coefficient and normal absorption coefficient, the coal thickness can be determined.

Key words: igneous rocks, coal thinning zone, tomography, absolute attenuation, radio wave perspective