OCCURRENCE AND AFFECTIVE GEOLOGICAL FACTORS OF COALBED GAS OF THE CARBONIFEROUS-PERMIAN IN THE EASTERN MARGIN OF ORDOS

Based on the contents of coalbed methane,the paper divided the eastern margin of Ordos into three regions: the northern region with low gas content, the middle region with high gas content and the southern region with middle gas content. Then, the major geological factors affecting the content of coalbed methane were discussed, including burial depth of coal seams, metamorphic degree, geological structures, coal thickness, roof and floor lithologies of coal seams and magma movement. Lastly, it is pointed out that the middle region with high gas content is a favourable target for exploration of coalbed methane.