多宝山矿集区斑岩型铜钼矿床岩(矿)石物性特征及其找矿标志

The Physical Characteristics of Rock (Ore) and Prospecting Indicator of Porphyry Cu-Mo Deposits in Duobaoshan Ore District

多宝山斑岩型铜钼矿床位于小兴安岭西北部,是中亚-兴蒙造山带北东段最大的斑岩型铜钼矿床,为了分析该矿床岩(矿)石综合物性参数及其之间的相互关系,探讨具有不同地球物理或地质意义的岩石物性参数组合,研究矿床(矿)石物性综合参数特征及其找矿标志,本文收集了大量的密度、磁性、电性资料,同时对该矿床中具有代表性的岩(矿)石进行了采集和测定,通过统计分析认为加里东期成矿岩体(花岗闪长岩、花岗斑岩复合型岩体)具有低密度、高磁特征,奥陶世多宝山组赋矿地层为高密度、低磁特征;对于多宝山斑岩型铜钼矿,重力方法不具备找矿物性前提,磁异常也不具备作为直接找矿标志,但对成矿母岩、成矿构造、矿化蚀变带的识别有重要的作用;主要载矿岩石(蚀变花岗闪长岩、蚀变安山岩质火山岩)具有高极化率、中低电阻率电性特征,而且随着矿石含矿品位提高,极化率值明显增大,形态规则,强度一般为6%～10%的视极化率异常可以作为直接找矿标志。

The Duboshan porphyry copper molybdenum deposit is located in the northwest- ern part of the small Xingan ridge. It is the largest porphyry copper molybdenum deposit in the eastern part of the Central East Xingmeng orogenic belt. In order to analyze the com- prehensive physical parameters of the rocks（ore） deposit and their interrelationships, to discuss the combination of physical parameters of rock with different geophysical or geolog- ical significance, the characteristics of comprehensive parameters of stony properties ofmineral deposits and their prospecting marks are studied. In this paper, a large number of density, magnetism and electricity data are collected, and representative rocks（ore） in this deposit are collected and measured. Through statistical analysis, it is considered that the Caledonian metallogenic rock mass（Granodiorite and granite porphyry complex rock mass） is characterized by low density and high magnetism and the Ordovician Duobaoshan group is characterized by high density and low magnetism. For the Duobaoshan porphyry copper molybdenum deposit, gravity method does not have the mineral prospecting premise, and magnetic anomalies also do not have the marks of direct prospecting, but they play an im- portant role in the identification of metallogenic parent rocks, metallogenic structures and mineralized alteration zones. The main ore bearing rocks （altered granite diorite and altered andesite volcanic rock） are characterized by high polarization and low-medium resistivity, and the polarizability increases with the ore grade of ore bearing ore. The anomaly of appar- ent polarization, whose intensity is 6-10%, can be used as a direct prospecting indicator.