Metallogenic Geological Characteristics And Metallogenic Prediction Of Qimantage Iron And Polymetallic Deposit Of East Kunlun Mountains

Qimantage metallogenic belt, the bond of the East and West Kunlun metallogenic belt, is the major ore concentrated area of iron, lead, zinc, copper, cobalt and other minerals in Qinghai Province. In this paper, under the guidance of the theories of minerogenetic series, plate tectonics and trace elements migration, and the mineral deposit models of skarn-type deposit, porphyry copper deposit and hydrothermal ore deposit, the author analyzed the regional geological setting, and studied geological and geochemical characteristics and controlling factors and metallogenic mechanism of Qunli Fe-Cu deposit, Kaerqueka copper deposit, Kendekeke Fe-Co-Au deposit in Qimantage area, and thus summed up the regional metallogeny, and established the regional metallogenic model.The following are major achievement obtained in this paper:1. Qimantage metallogenic belt is bounded by the North-Kunlun fault to the north and the South-Kunlun fault to the south. The stratigraphic sequence cropping out in the study area ranges from Upper Archean to Cenozoic in age. Magmatic rocks occur widely in the study area, mainly consisting of Variscan to early Indosinian and late Indosinian to Himalayan intermediate-acid intrusive rocks. The tectonic evolution of the Qimantage area is generally subdivided into four stages: (1) the formation of the ancient Qaidam plate(2500 - 513Ma) through cratonization for three times; (2) the formation of Western China Craton (513—386Ma) through the subduction between several islands in North and Middle Kunlun Mountains; (3) the formation of the reverse fault zone in the northern margin of Kunlun Mountains(386 - 0.78Ma), with the opening, evolution, and closure of the ancient and the Neo- Tethys Ocean and acidic magma intrusion; (4) The uplift of the East Kunlun Mountains (0.78 to now), marked the beginning of the Neotectonic Movement. The first and second stages played an important role in mineralization of the area.2. Indosinian granite in the study area is of great significance for mineralization. Based on the 5 Eu value, the study suggest that the granite in contact zone between granite and wall-rock formed by assimilation, and the granite in the inner of granitic body generated by crystallization.3. Granite and carbonate contact metasomatism and mineralization occurred simultaneously. The carbonate strata consist of the Baishahe Formation in Jinshuikou Group, the Tanjianshan Group and the Upper Paleozoic Di'aosu group. Faults control mineralization by defining the distribution of igneous rocks which controls orebody indirectly, by leading ore mining from the deep role, or by generating various types of fracture system in strata to control the distribution of ore bodies.4. Polymetallic metallogenic series related to Indosinian period granite developed in the studying area: contact zone- and fracture-related skarn-type Fe-polymetallic deposits developed in carbonate area, porphyry-type copper-molybdenum deposit occurred in the fracture of porphyry body, and hydrothermal silver, gold and cobalt ore deposit formed in the fracture of siliceous rocks and blastoclastic rocks.5. By analyzing integrated geological and prospecting information, metallogenic prediction and mining prospecting is evaluated and it is proposed that porphyry copper deposit could prospect in the depth of the Siyangjiao polymetallic ore district, skarn-type Fe-polymetallic deposit could prospect around C4 magnetic anomaly zone in Siyangjiao and Wulanbaixing ore district, and hydrothermal Fe-polymetallic deposit could prospect around Mohexiala and Lalingzaohuo polymetallic ore district.