CHARACTERISTICS OF EXTENSIONAL STRUCTURES IN WESTERN SHANDONG AND THEIR INFLUENCE ON COAL MINE PRODUCTION

The geological henomena that high angle normal faults and a series of graben or semi-graben types of faulted basins in nearly EW or SN directions developed widely in western Shandong indicated that this area suffered large scale extensional movement in Mid-Kainozoic.The accumulated horizontal displacement in basement is up to more than 30 km.The extensional structures not only control the occurrence and distribution of coal,oil and gas basins,but also influence the structure development in mining area,hydrological conditions and gas storage.