Evolution of Triassic volcanic-sedimentary basins in the central segment of the Yidun island arc of the Songpan-Garzê orogenic belt,western Sichuan,China;

Age of intraplate volcanism in the back-arc area of Yidun island arc and its significance;

Zhujiding porphyry copper deposit is located in the north part of the "Three-river" metallogenic belt,and in the south part of non-ferrous and precious metal concentration region of Yidun island arc.

The Nongduke deposit is the first volcanic epithermal Au_Ag polymetallic deposit found in the Yidun arc zone.

As a composite orogenic belt of the Himalaya giant orogenic zone, Yidun arc, Sanjiang region (means three rivers region, i.

Since the middle and late Caledonian, the two basins beg3n opening and closins,and three subduction zones, two collision zones andseven island arc belts were formed.

Lying in a special geotectonic position and undergoing complicated geological evolution and strong magmatism, Yidun metallogenic belt is rich in mineral resources.