Abstract:

Abstract:  Coal is an organic rock which is sensitive to geological environmental factors such as temperature and pressure. Various tectonothermal events of the geological evolution  must have caused a series of changes  in physical, chemical structures of coal and thus formed different tectonically deformed coals. The effect of tectonic stress would induce the brittle and ductile deformation of coal, as well as its dynamic metamorphism at different degrees. Therefore the research about tectonic deformation and dynamic metamorphism of coal is not only of important scientific significance but also very important for the evaluation in resources of coalbed methane and the  prediction of dangerous coal and gas outbursts. Based on the existing research results, different tectonic deformation and dynamic metamorphism in coal have been intensively studied through the Ro,max,XRD and NMR(CP/MAS+TOSS). Also the mechanism of dynamic metamorphism about coal under tectonic stress has been discussed. The results show that,under the influence of tectonic stress to the brittle deformation of coal, the rapid mechanical friction on the plane of fracture in the brittle deformation of coal can be translated into heat energy causing the changes of its chemical structure and composition of coal; while as to the ductile deformation coal,the accumulation of local regional strain energy can result in the failure of its chemical structure. Thus the dynamic metamorphism of different deformational mechanisms would have taken place.

Key words:

Key words: coal; tectonic deformation; tectonically deformed coal; dynamic metamorphism;mechanism