西昆仑托日提乌托克铜(金)矿点岩石地球化学、年代学特征及地质意义  

Age and Geochemical Characteristics of the Tuoritiwutuoke Copper(gold)Occurrence in Western Kunlun and Their Geological Significance

作　　者：张荣臻[1,2,3] 张德会 杜保峰[2,3] 胡红雷[2] 朱红运 韩亚 宾朝晖 ZHANG Rongzhen;ZHANG Dehui;DU Baofeng;HU Honglei;ZHU Hongyun;HAN Ya;BIN Chaohui(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Henan Institute of Geological Survey,Zhengzhou 450001,Henan,China;Henan Key Laboratory for Metal Mineral Ore-forming Geological Process and Utilization of Resource,Zhengzhou 450001,Henan,China;Henan Geological Science Research Institute,Zhengzhou 450001,Henan,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]河南省地质调查院,河南郑州450001 [3]河南省金属矿产成矿地质过程与资源利用重点实验室,河南郑州450001 [4]河南省地质科学研究所,河南郑州450001

出　　处：《大地构造与成矿学》2022年第4期677-690,共14页Geotectonica et Metallogenia

基　　金：中央返还新疆地质勘查基金项目(K15-1-LQ01);国家自然科学基金项目(41373048、41773030)联合资助。

摘　　要：托日提乌托克铜(金)矿点是新疆西昆仑地区新发现的达到铜工业品位的矿点,铜(金)矿化与斑状石英二长岩体有关。为了确定矿点及含矿岩体的成因与形成的构造背景,并评价其找矿潜力,本文对斑状石英二长岩进行了岩石地球化学和锆石U-Pb年代学等研究。结果表明,该铜(金)矿点为一受构造控制的岩浆热液型矿点。斑状石英二长岩整体具有富硅(SiO_(2)=54.43%~69.61%)、富铝(Al_(2)O_(3)=14.38%~16.75%)和富碱(Na_(2)O+K_(2)O=8.44%~8.82%)等特征,富集大离子亲石元素,亏损高场强元素,属于偏铝质的高钾钙碱性Ⅰ型花岗岩类,轻重稀土元素分馏明显,具有弱Eu负异常,为典型的岛弧岩浆岩,是新生地壳部分熔融和壳源沉积物混染的结果。锆石U-Pb同位素测年获得成岩年龄为483.4±3.7 Ma,表明该岩体形成于早奥陶世,与大同地区加里东期的岩浆活动时间一致,为原特提斯洋向南北昆仑地体双向俯冲环境下的产物;岩石地化特征及已有探矿工程表明该矿点元素异常明显、见矿良好且剥蚀程度不高,具有较好的找矿潜力。The Tuoritiwutuoke copper(gold)ore occurrence is a newly discovered ore showing with industrial grade copper ores in the Western Kunlun area.The ore mineralization is closely associated with a porphyritic quartz monzonite intrusion,while the age and genesis of the quartz monzonite and geological features of the ore occurrence remain unclear.In order to delineate the origin and tectonic setting of the ore-bearing pluton,and to evaluate its ore potential,the geochemical compositions and zircon U-Pb age of the quartz monzonite were analyzed.The results showed that the ore occurrence is of magmatic hydrothermal type,controlled by structures.The porphyritic quartz monzonite is characterized by high contents of SiO_(2)(54.43%to 69.61%),Al_(2)O_(3)(14.38%to 16.75%)and Na_(2)O+K_(2)O(8.44%to 8.82%),enriched in LILE,and depleted in HFSE.The rock samples show right-dipping chondrite normalized REE patterns with weak negative Eu anomalies.The quartz monzonite shows trace element signatures of typical island arc magmatic rocks,and high potassium and calc-alkaline metaluminous features,and belongs to Ⅰ-type granite.The zircon U-Pb dating yielded an age of 483.4±3.7 Ma,which is consistent with the early Ordovician magmatic activity in the Datong area during the Caledonian period which are likely related to the subduction of the Paleotethys to the north and south Kunlun terrane.The geochemical characteristics of the pluton and the prospecting results indicate that the ore occurrence has a very promising potential for ore-prospecting.

关 键 词：西昆仑 托日提乌托克 铜(金)矿点 斑状石英二长岩 锆石U-Pb年龄 构造环境 

分 类 号：P597[天文地球—地球化学] P595[天文地球—地质学]