Analysis on the geochemical characteristics of Chachalongwa copper, lead and zinc polymetallic ores

2018 1st International Conference on Environment Prevention and Pollution Control Technology

生态环境科学

Wang, Jianguo^1 ; Zhang, Wen^1 ; Zhang, Yifan^1 ; Tian, Faming^1 ; Duan, Yunying^1 ; Sun, Wenyu^1

Department of Geological Engineering, Qinghai University, Xining

810016, China^1

关键词: Geochemical characteristic;    Geological age;    Magma differentiation;    Magma evolution;    Mineral assemblage;    Partition modes;    Polymetallic ores;    Volcanic activities;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/199/4/042043/pdf
DOI  :  10.1088/1755-1315/199/4/042043

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The tectonic position of the Chachalongwa Cu, Pb, Zn polymetallic ores is located at the junction of the Qinqi - Kun orogenic system and the eastern Kunlun arc basin system. Through analysis of mineral assemblage, trace elements, rare earth elements, tectonic background and geochronology, the lithology, rock assemblages, geochemical characteristics of each ore-bearing strata in Xianqilongwa have been found out. It is found that the ore - bearing strata are volcanic rocks of the late Triassic Elashan Formation. As can be seen from the TAS diagram of principal elements, the magma evolution is in the direction of rich silicon, alkali, and poor magnesium, iron. the more that the magma differentiation, the higher that acid degree. From the diagram of rare earth partition mode, it can be found that the curve is inclined to the right, and is a negative Eu type of LREE enrichment. As the acidity of the rock increasing, the contents of elements such as Cu, Zn, Ni, Co, V, Ti, Mn and Sr are decreased, and compared with Taylor's crustal abundance, the content of elements such as Pb, Zn, Cr, Ga and Sn increased gradually. According to the geological tectonic environment, it can be roughly determined that the tectonic environment is the volcanic rock area of the orogenic belt, it shows that the volcanic rocks is in the tectonic orogenic belt environment. The age obtained by Rb - Sr and K - Ar methods was 210 ± 14Ma - 235 ± 12Ma, it shows that the geological ages of volcanic activity is the late Triassic, and the period of volcanic activity is not so long.