Abstract:

Yuchiling porphyry Mo deposit is a new type deposit  which can be  seen in post-collisional Orogenic belt.In this paper，the author has  centigramed the main alteration of wall rocks and the spreading pattern in  space，ascertaining the relationship of mineralization and veins，and  investigatting the mechanism of fine granite and veins，and setting up the  deposit model initially by detailed research for geology，alteration  and，  mimneralization.By this，we can come to a conclusion that the fine granite  and early veins are the results of evolving porphyry granite and ore-rock，however，the earlier veins and final veins are the results of fluid  exsolution  of the fine granite.The ore-rock has been altered at the same time，that are  the  earlier potassium，the later muscovit-quartz alteration sericitization，phyllic alteration and the latest carbonation alteration and argillic alteration.The  alteration type and intensity of the deposit are no change almost in vertical  direction，but the alteration type and intensity of the deposit have obvious  changes in the horizontal direction.We know now that the main mineralization  occurred along with the muscovite-quartz alteration and the mineralization  type are veinlet and stockwork mainly.

Key words: Alteration, Mineralization, Ditribution of veins, Porphyry Mo deposit, Yuchiling, Eastern Qinling Moutains