论文部分内容阅读
新疆西天山斑岩铜矿找矿勘查备受关注。乌兹别克斯坦Almalyk斑岩铜矿田处在西天山西段,铜矿规模属亚洲第二大,但其成矿时代还没有准确厘定。在区域地质构造中,Almalyk铜矿田位于中天山加里东—华力西褶皱带南部边缘,包括Kalmakyr、Dalneye、Sarcheku和Kyzata等4个铜矿床,铜成矿主要发生在斑岩体内,原生矿石呈网脉状、浸染状,金属矿物主要有黄铁矿、黄铜矿,辉钼矿、赤铁矿、磁铁矿、自然金、斑铜矿等。针对Sarcheku铜钼矿石中辉钼矿利用Re-Os法测得(320.4±2.3)Ma的模式年龄和(317.6±2.5)Ma的等时线年龄。结合岩浆建造序列,认为矿田内构造—岩浆—热液过程开始于早石炭世,发展于晚石炭世,结束于早二叠世,斑岩型铜成矿主要在晚石炭世。西天山包括Almalyk铜矿田在内大型—超大型斑岩型铜成矿作用主要在中泥盆—晚石炭世(D2—C2),与古亚洲洋壳向哈萨克斯坦—伊犁板块之下俯冲形成的复杂岛弧岩浆地质过程有关。
The prospecting exploration of the West Tianshan porphyry copper deposit in Xinjiang has drawn much attention. The Almalyk porphyry copper ore field in Uzbekistan is located in the western part of the Western Tianshan Mountains. Its copper deposit is the second largest in Asia, but its mineralization age has not been accurately determined. In the regional geological structure, the Almalyk copper ore field is located on the southern margin of the Caledonian-Hurricin fold belt in the Tianshan Mountains, including 4 copper deposits such as Kalmakyr, Dalneye, Sarcheku and Kyzata. The copper mineralization occurs mainly in the porphyry, Primary ore was reticular, disseminated, metal minerals are pyrite, chalcopyrite, molybdenite, hematite, magnetite, natural gold, bornite and so on. The model age of (320.4 ± 2.3) Ma and the isochron age of (317.6 ± 2.5) Ma were determined by Re-Os method for the molybdenite from Sarcheku copper-molybdenum ore. Based on the sequence of magma construction, the tectono-magmatic hydrothermal process in the ore field began in the Early Carboniferous, developed in the Late Carboniferous and ended in the Early Permian. The porphyry copper mineralization was mainly in the Late Carboniferous. The large-superlarge porphyry-type copper mineralization in the western Tianshan including the Almalyk copper ore field is mainly caused by the subduction of the Middle Devonian-Late Carboniferous (D2-C2) with the sub-Asian oceanic crust to the Kazakhstan-Ili plate The complex island arc magmatic geological process.