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Granitic rocks,widely developed in the Lamasu copper ore region,western Tianshan were formed at 390.5±7.7 Ma according to the SHRIMP zircon U-Pb dating of the plagioclase granite porphyry.Based on the regional tectonic evolution and published chronological data of both diagenesis and mineralization,the Biezhentao-Kokirqin region was rolled into the orogen associated with the closure of Yili Ocean during early Devonian.The N-S-trending thrust faults were formed during this period and accompanied by the intrusion of granitic rocks.On this stage,the paleo-Asian Ocean Plate entered into the early collision orogenic phase and the plagioclase granite porphyry intruded(390.5±7.7 Ma)and replaced with limestone of the Mesoproterozoic Kusongmuqieke Group,Jixianian System and formed the early phase of skarn-type copper mineralization in the Lamasu region.Furthermore,the subduction-melting of Bayingou Ocean Plate during Carboniferous generated a deep-seated magmatic chamber in the Lamasu copper ore region which located in the northwestern part of the Paleozoic Biezhentao-Kokirqin island arc.The magmatic chamber segregated Cu-bearing magmas,which transported upward to the shallow earth crust along the faults or fractures and formed the Cu-hosting porphyry.According to the research on the characteristics of the ore deposit and the ore-forming environment as mentioned above,the Lamasu Cu-Zn deposit was characterized by the superposing of mineralization at different geological settings and it was skarn-porphyritic type.
Granitic rocks, widely developed in the Lamasu copper ore region, western Tianshan were formed at 390.5 ± 7.7 Ma according to the SHRIMP zircon U-Pb dating of the plagioclase granite porphyry. Based on the regional tectonic evolution and published chronological data of both diagenesis and mineralization, the Biezhentao-Kokirqin region was rolled into the orogen associated with the closure of Yili Ocean during early Devonian. The NS-trending thrust faults were formed during this period and accompanied by the intrusion of granitic rocks.On this stage, the paleo- Asian Ocean Plate entered into early collision orogenic phase and the plagioclase granite porphyry intruded (390.5 ± 7.7 Ma) and replaced with limestone of the Mesoproterozoic Kusongmuqieke Group, Jixianian System and formed the early phase of skarn-type copper mineralization in the Lamasu region. Furthermore, the subduction-melting of Bayingou Ocean Plate during Carboniferous generated a deep-seated magmatic chamber in the Lamasu copper ore region which located in the northwestern part of the Paleozoic Biezhentao-Kokirqin island arc. the magmatic chamber segregated Cu-bearing magmas, which transport upward to the shallow earth crust along the faults or fractures and formed the Cu-hosting porphyry. Accredited to the research on the characteristics of the ore deposit and the ore-forming environment as mentioned above, the Lamasu Cu-Zn deposit was characterized by the superposing of mineralization at different geological settings and it was skarn-porphyritic type.