Darreh Zereshk porphyry copper deposit inSouth-west of Yazd
|Category||Economic geology & mineral exploration|
|Location||21th symposium on geosciences|
|Holding Date||21 May 2008|
Granitoid rocks in Darreh Zereshk in SW of Yazd are porphiritic alkali feldspar granite, porphyritic granodiorite and cataclastic porphyritic granite. Trachyandesitic dykes observed within these rocks. Besides, metamorphosed rocks (Garnet-bearing skarns with Grossular and andradite garnet) are considerable. They commonly are zoned with massive garnetite near the pluton and expansion epidote near the contact of marble.
Copper deposit of Darreh-Zereshk is formed by intrusion of granitoid stock. It is porphyry copper deposits like Lowel-Guilbert Model with fewer amounts of molybdenum and magnetite. Thus the copper deposit of Darreh-Zereshk was formed by skarn and porphyry deposit.
The skarn has higher grade but porphyry has higher reserve. The granitoid rocks in this area belong to sub-alkaline rocks with calc-alkaline composition.
At the mineralized zones with increasing SiO2, the amount of Cu has increased so it seems the Cu has been incompatible in granitoid magma and to be concentrating in segregated melts.
Genetically Darreh Zereshk is the I?type granite that have formed of melted infracrustal and observed trace elements. From economical potential point of view, mineralization of Cu, marble, garnet-bearing skarns, and non-metalic minerals such as kaolinite are considerable.
It seems that the intrusive bodies of Darreh Zereshk are younger than metamorphosed rocks resulting of the Early Cretaceous Orbitolinid bearing limestones near them