西藏尼木岗讲斑岩铜钼矿床地质特征及深部找矿预测

发布时间：2018-06-01 19:49

本文选题：铜钼矿 + 区域地质背景　；参考：《金属矿山》2017年04期

【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。
[Abstract]:The Gangliao copper-molybdenum deposit is a typical porphyry deposit in the middle section of the Gangdis metallogenic belt, Tibet. In order to find a breakthrough in prospecting and quicken the pace of prospecting in Gangliao mining area, based on the results of geological work in the area, this paper analyzes in detail the regional metallogenic geological background, geological characteristics of mining area, orebody features, ore features and alteration characteristics of surrounding rock. And the EH-4 magnetotelluric sounding method is used to carry out the deep prospecting and prediction work. The study shows that the horizontal projection of the Wei 1 orebody is U-shaped with an opening to the west, the Erchang granitic porphyry is the main ore-hosting rock, the late granodiorite porphyry, the stream porphyry and the Yingyun diorite porphyry destroy the orebody. The ore body grade of further reformation and enrichment has the characteristic of single peak distribution. The Cu grade is mainly concentrated in 0.2and 0.4Mo grade, and the ore body thickness in the north section is obviously larger than that in the southern ore body, and the Mo grade is mainly concentrated in 0.01- 0.03 ore body, and the ore body in the north section is obviously thicker than the ore body in the south section. The grade of the southern ore body is slightly higher than that of the northern ore body. Combined with the existing prospecting engineering data, the inversion results of EH-4 survey are interpreted. Class A high resistivity electrical bodies (apparent resistivity 1 800 ~ 3 600 惟 m / m) and C type low resistivity bodies (apparent resistivity less than 400 惟 m ~ (-1) and C type low resistivity bodies (< 400 惟 m ~ (-1) have been delineated. The low resistivity anomalies of C _ (2) are distributed in long axis near the surface of the earth's surface, with a nominal height of 4 800 m. It may be that the low resistivity anomaly of C _ 1 caused by oxidized ore (chemical) body has a large scale and has a good continuity to the deep. It is assumed that the measurement of 1: 10 000 IP ladder caused by the deep primary ore (chemical) body shows that the C1C _ 1 / C _ S _ 2 anomaly is more likely to be a ore-induced anomaly. The prospect of deep prospecting is good. On the basis of the above analysis, this paper summarizes in detail the direct prospecting markers (mineralized outcrop) and indirect prospecting markers (alteration, structure, geophysical anomalies, etc.), which have certain reference value for further deep prospecting and prediction in the area.
【作者单位】：中国地质大学(武汉)资源学院;云南铜业(集团)有限公司;
【基金】：国家重点基础研究发展计划(973计划)项目(编号:2009CB421007)
【分类号】：P618.41;P618.65

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