期刊名称：IOP Conference Series: Earth and Environmental Science
印刷版ISSN：1755-1307
电子版ISSN：1755-1315
出版年度：2018
卷号：199
期号：4
页码：042043
DOI：10.1088/1755-1315/199/4/042043
语种：English
出版社：IOP Publishing
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.
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