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Chen X.,China University of Geosciences | Yuan W.,China University of Geosciences | Zhang A.,Third Institute of Qinghai Geological Mineral Prospecting | Hao N.,China University of Geosciences | And 2 more authors.
He Jishu/Nuclear Techniques

Background: Qimantage is an important tectonic metallogenic belt in western part of East Kunlun Mountain. It has experienced complex geological evolution, and significant mineralization. However, because of the plateau climate and inaccessibility, fewer research works have been done on this area, especially after Indo-sinian epoch. Purpose: Our work is to research tectonic activity, thermal history and uplifting around Bayinguole river in Qimantage belt. Methods: The apatite fission-track method was applied to research the tectonic setting, simulate the thermal history and calculate the uplift size and uplift speed. Results: A series of apatite fission track ages from granitoid samples in Bayinguole area of Eastern Kunlun Mountain were obtained, ranging from 120 Ma to 47 Ma that might be divided into three groups: 120-100 Ma, 67 Ma and 54-47 Ma. These ages reflected tectonic events in this area very well. Conclusions: The 120-100 Ma and 67 Ma ages present collision-convergences of Gangdese terrane and Himalayan terrane with their north-side terranes in Early Cretaceous and Late Cretaceous respectively. The ages of 54-47 Ma reflect post-orogenic stretching events in Eocene. Three stages of thermal evolution history are revealed by apatite fission track modeling in this area. Stage one 180-140 Ma is in the bottom temperature of apatite fission track anneal zone. Stage two 140-13 Ma records slow cooling. The last stage after 13 Ma records rapid cooling with temperature dropped 50°C. The uplifting ranges for these three stages are 1.0 km, 0.6 km and 1.4 km, respectively. The cumulative amount of uplift is about 3.0 km. The formular calculations for the 3 samples have their rock uplifts of 3623 m, 3317 m and 3769 m, respectively, averaging 3570 m, in accordance with the results based on the 3 stage thermal history. Source

Lai J.,Central South University | Huang M.,Central South University | Song W.,Central South University | Song W.,Hunan Research Academy of Geological science | And 2 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences

Combined with field investigation and ore-forming geological conditions of the Kaerqueka copper polymetallic deposit, the geochemical characteristics of the deposit are summarized, the origin of the ore-forming materials is ascertained, and the rock-forming and ore-forming mechanisms are discussed according to the S, Pb isotopes as well as chemical analysis, including major element analysis, trace element analysis. Results of typical magmatic rocks, wall rocks and ores show that the magmatic rocks which were derived from deep and affected by crustal contamination during intrusion are intermediate acidity comagmatic rocks and belong to the high-K calc-alkaline series. All REE distribution patterns of different geologic bodies incline to the right and LREE-rich, indicating that the magmatic rock, skarn and ore belong to the same metallogenic system. The geochemistry of trace elements shows that the granites of the deposit occurred in volcanic arc environment. The δ34SCDT values of ore minerals lie between those of magmatic rock and country rock sulfur, with a range of 4.4‰ to 11.0‰, which indicates various metallogenic material sources. The Th/U values of lead isotope in ore minerals range from 3.46 to 3.69 and the μ values range from 9.46 to 9.52 (<9.58), which fall between the values of crust and primitive mantle and indicate that the ore lead is characterized by both deep-sourced and crust-sourced origins. The tracer analysis regarding the characteristic parameters, lead composition model and Δβ-Δγ diagram show that the ore lead is mainly crust-derived and mixed with minor mantle-derived lead and affected by magmatism. The geochemical characteristics of Kaerqueka deposit suggest that the ore-forming materials mainly originated from magma with minor strata substance. The complicated evolution of magmatic rock is revealed by the porphyry-type copper-molybdenum mineralization in magmatic rock, the skarn-type lead-zinc mineralization following the contact of carbonate rock and the late low-medium hydrothermal vein-type gold mineralization, which indicates the Kaerqueka deposit is a polygenetic compound deposit. ©, 2015, China University of Geosciences. All right reserved. Source

Lei Y.-B.,Central South University | Lei Y.-B.,Hunan Institute of Geology Survey | Lai J.-Q.,Central South University | Wang X.-J.,Central South University | And 3 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals

Hutouya deposit is one of the typical Pb-Zn polymetallic deposits in Qimantage region. This deposit was divided into 4 metallogenic epoches and 7 mineralization stages based on geological characteristics of ore and identification of polished sections and thin slices. There were 16 representative minerals selected from sulfides and measured to determine the values of S and Pb isotopes. The results show that the values of δ(34S) range from +0.6×10-3 to +9.8×10-3, in which the average value is +5.2×10-3, and increase gradually from the edges of intrusions to the distal end of them, while the range of Pb isotope is small, with 38.717-38.261 for 208Pb/204Pb, 15.718-15.560 for 207Pb/204Pb, 19.502-18.476 for 206Pb/204Pb. Associated with characteristics of the ore deposit and the results of the former researchers, the characteristics of S and Pb isotopes were analyzed, and the proportions of Pb in the crust and mantle are estimated to be 0.07-0.22 and 0.78-0.93, respectively. The sources of metallogenic material are speculated from the magmatite that is composed of large ratio of crust matter and small proportion of mantle. The evolution of metallogenic material is that S element has higher proportion of igneous rocks' matter when mineralization is adjacent to magmatite, and with larger percentage of strata in distal area; however, the main materials still originate from intrusions. ©, 2014, Science Press. All right reserved. Source

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