THE MECHANISM OF MINERALIZATION IN CHONGLI-CHICHENG GOLD-BEARING SHEAR BELT,NORTHWEST OF HEBEI PROVINCE

The unique gold-bearing shear belt is well developed in Northwest Hebei.The intensive ductile shearing deformation and complicated alkali metasomatism are well developed during Indosinian-Yanshanian period.The mylonites and alkali metasomatic complex as well as different gold deposits are the terminal evolution result of the shearing deformation and alkali metasomatism, The high Au element background in the greenstone and the intensive ductile shearing deformation as well as the evolution are the basis of gold concentration,the multiple dimensional-fracture type alkali metasomatism of gold-bearing and alkali-riched hydrothermal fluid which was associated with the deformation evolution from ductile to brittle is the key processes for ore-forming.