摘要
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 exploration of porphyry copper deposits in western Tianshan, Xinjiang, had attracted much attentions. The Ahnalyk copper deposit in western Tianshan, Uzbekistan, is one of the largest porphyry copper deposits in Asia, but has not well been dated. The Almalyk copper ore field is located in the southern part of Caledonian Hercynian central Tianshan fold belt, and includes four copper deposits： Kalmakyr, Dalneye, Sarcheku and Kyzata. Copper mineralization occurred within the porphyries. The primary ores are character ized mainly by stockwork and disseminated structures, and the major metallic minerals are in assemblage of py rite, chalcopyrite, molybdenite, hematite, magnetite, nature gold and hornite. The present paper obtains the weighted model age of 320.4--2. 3 Ma and an isochron age of 317. 6!2. 5 Ma based on tile Re^Os isotopic method by using the molybdenites from the Sarcheku copper-molybdenum ores. On the basis of the sequence of magmatic formation in this area, it is suggested that the tectonomagmatic hydrothermal process in Ahnalyk ore field started at the early Carboniferous, developed during the late Carboniferous, and finished at the early Permian, and the porphyry copper mineralization mainly occurred during tile late Carboniferous. The world class large and supper large porphyry copper mineralization including the Almalyk copper deposit in western mianshan is closely related to the complex arc magmatic geological processes resulted from the subduction of paleo-Asia ocean crust under Kazakhstan-Yili plate, which happened mainly from the middle Devonian to the late Carboniferous （D2-C2）.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2013年第2期197-204,共8页
Earth Science Frontiers
基金
“十二五”国家科技支撑计划重点项目(2011BAB06B02)
地质过程与矿产资源国家重点实验室开放基金项目(GPRM200832)
