Determination of Coal Seams Depth of Erosion with Respect to the Remnants of a Key Bed in Kerman Coal Field, Iran

As a tool for exploration of concealed coal seams by modern techniques, determination of the depth of erosion of coal seams with reference to the surface of angular unconformity underlying the remnants of a key bed is conducted for the first time in coal mines of Kerman region. The angular unconformity surface (the initial surface exposure of coal seams) separates the coal seams of Jurassic age from thick limestone beds of Cretaceous age (key bed) in the coal synclinorium of Kerman region. Frequent tectonic deformation in Cenozoic led to the exhumation of portions of Cretaceous limestone (key bed) together with the coal seams of Jurassic age. The initial surface exposure of coal seams which is referred to as the "initial surface" herein, determines the upper limit of the coal seams in Early Cretaceous and is used as a "reference surface". After importing and processing the available information, namely, satellite data, field survey data, geological maps, topographic and hypsometric data, Global Positioning System (GPS) data and geo-structural data of the reference surface and present surface exposure of coal seams into GIS software, the depth of erosion of coal seams between the "initial surface" (reference surface) before erosion and the "present surface" after erosion was calculated. It is concluded that the depth of erosion of coal seams in northern region is higher than the southern region. Therefore, the remnant of the coal seams (concealed coal seams) along the dip direction is higher in the south as compared to the northern sector.