Discovery and Significance of Yulekenhalasu Porphyry Copper Deposit on Northeast Margin of Junggar

Based on the geological survey,as well as the indoor research on petrography and mineralography and available data,the newly discovered Yulekenhalasu porphyry copper deposit is investigated.The results show that the two ore-bearing rock-bodies in Yulekenhalasu porphyry copper deposit,occurred in the suture zone between Kazakhstan-Junggar plate and Siberian plate,have similar mineralization characteristics.Mineralization is found in the whole rocks and pyrite and chalcopyrite are the main metallic minerals.The spatial alteration zones from the ore body to the outer side are K-feldspar alteration zone,biotite alteration zone,sericitolite alteration zone and propylite alteration zone and they can be distinguished clearly.The results from the H,O,S isotope show that the ore-forming fluids are magmatic water mixed with meteoric water,and the ore forming materials are originated from the mantle.The two ore-bearing rock-bodies are formed in the Middle Devonian(381.6±2.5Ma) and Early Permian(265.6± 3.7Ma).And therefore porphyry copper deposits in the Halasu district are formed not only in the island arc background,but also in the extensional environment after collision.