摘要
岗讲铜钼矿床为西藏冈底斯成矿带中段典型的斑岩型矿床。为寻求岗讲矿区找矿突破,加快区内探矿工作步伐,基于区内地质工作成果,详细分析了区域成矿地质背景、矿区地质特征、矿体特征、矿石特征、围岩蚀变特征,并采用EH-4大地电磁测深手段开展了深部找矿预测工作。研究表明:1矿体水平投影呈开口向西的U形展布特征,二长花岗斑岩为主要的赋矿岩石,后期花岗闪长斑岩、流纹斑岩、英云闪长玢岩等对矿体起到破坏、进一步改造富集的作用。2矿体品位具有单峰分布特征,Cu品位多集中于0.2%~0.4%,Mo品位多集中于0.01%~0.03%,北段矿体厚度明显大于南段矿体,南段矿体品位略高于北段矿体。3结合矿区已有的探矿工程资料,对EH-4测量反演成果进行了地质解译,圈定出了A类高阻电性体(视电阻率1 800~3 600Ω·m)、B类中阻电性体(400~1 800Ω·m)以及C类低阻电性体(视电阻率小于400Ω·m),其中,C_2低阻异常呈长轴状分布于近地表附近,标高4 800 m以浅,可能为氧化矿(化)体所致,C_1低阻异常规模较大,向深部具有较好的连续性,推测为深部原生矿(化)体所致;1∶10 000激电中梯测量验证表明,C_1、C_2异常为矿致异常的可能性较大,深部找矿前景较好。在上述分析的基础上,详细总结了直接找矿标志(矿化露头)和间接找矿标志(蚀变、构造、物探异常等),对于区内进一步进行深部找矿预测有一定的借鉴价值。
Gangjiang Cu-Mo deposit is a typical porphyry deposit,which is located in the Central Gangdese metallogenic belt. In order to seek the prospecting breakthrough and speed up the progress of the prospecting work of Gangjiang mining area, based on the geological study results of the mining area, the regional geological background, geological characteristics of the mining area and ore-bodies, ore characteristics, wall rock alteration characteristics are analyzed in detail, and the deep prospecting prediction of the mining area is conducted by adopting EH-4 magnetotelluric sounding method. The study results show that：①The horizontal projection of the ore-body with the U-shaped distribution characteristics, which opening to the west, the main ore-bearing rock is monzonitic granite porphyry,the later granodiorite porphyry, rhyolite porphyry and tonalite-porphyrite destroy the ore-body shape, meanwhile, they play a further role in the transformation and enrichment of ore-bodies. ②The grade value of the ore-bodies has single peak distribution characteristics, Cu grade value is more concentrated between 0.2% and 0. 4% ,and Mo grade value is more concentrated between 0. 01% arid 0. 03% ,the thickness of the northern ore-bodies is sig- nificantly greater than the one of southern ore-bodies in the mining area, but the grade value of the southern ore-bodies is slightly higher than the one of southern ore-bodies in the mining area, ③Combing with the existed prospecting engineering data of the mining area, EH-4 measurement inversion results of the mining area is conducted geological interpretation, the class A high resistance electrical body （which apparent resistivity is 1 800 - 3600Ω · m）, Class B medium-resistance electrical body （which apparent resistivity is 400 - 1 800 Ω· m） and class C low resistance electrical body （which apparent resistivity is lower than 400 Ω· m） , among them, C2 low resistance anomaly is distributed near the surface, which elevation is lower than 4 800 m ,is may be caused by oxidized ore-bodies or mineralized bodies ,the scale of C1 low resistance anomaly is relative large, the continuity of the anomaly to the deep is good,it is inferred that C1 anomaly may be caused by the deep native ore-bodies or native mineralized bodies ;the verification results of IP ladder measurement indicated that C1 and C2 anomaly are mostly likely caused by ore-bodies ore mineralized bodies. Based on the above analysis results, the direct prospecting indicator （mineralized outcrop） and indirect prospecting indicators （alteration, structure, geophysical anomalies, etc） of the mining area are summarized, to provide some reference for the deep prospecting prediction of the mining area.
出处
《金属矿山》
CAS
北大核心
2017年第4期105-112,共8页
Metal Mine
基金
国家重点基础研究发展计划(973计划)项目(编号:2009CB421007)
关键词
铜钼矿
区域地质背景
地质特征
EH-4大地电磁测深
深部找矿
找矿标志
Cu-Mo deposit, Regional geological background, Geological characteristics, EH-4 magnetotellurie sounding method, Deep prospecting, Prospecting indicator
作者简介
杨震（1988-），男，博士研究生。
通讯作者杨明国（1961-），男，讲师。
