【摘要】 VLF、EH4和CSAMT均为基于电磁原理的地球物理手段,但它们在探测深度、测量精度和野外操作的复杂程度上有较大的差异.因而不同探测目标和精度要求,尽可能使用不同的方法或方法组合.VLF一般用于矿区及外围的地球物理扫面,以快速确定和发现覆盖层(不超过50～60m)之下矿化构造系统的空间展布和基本规模.CSAMT具有探测深度大(>2000m)、工作效率高和抗干扰能力强等特点,一般用于确定矿化系统的深部的宏观几何形态和产状变化.EH4是这三种方法中对地下地质结构解析度最高、有效探测深度适中(800～1200m)的一种地球物理测深方法,它可以解析较为精确地探测矿体的三维形态、规模、产状变化和细部结构但采集数据时对近场电磁干扰要求较高.这三种地球物理方法在赤峰柴胡栏子金矿区的联合应用,为寻找覆盖层之下隐伏矿体取得了良好的效果.更多还原

【Abstract】 VLF, EH4 and CSAMT geophysical systems belong to electromagnetic survey methods with varying detection resolutions, depths of penetration and extents of operating complexities linking to cost\|effective choices. Therefore, an appropriate surveying method or method combinations should be applied for different stages of exploration and detecting purposes. Because of its reconnaissance nature and low-cost operation, VLF is typically utilized as a routine geophysical survey to, fast and effectively, detect and delineate near-surface (burden thickness less than 50～60 m) extensions and general sizes of ore\|controlling structures in a relatively large area. As an alternative, CSAMT has a powerful capacity of deep penetration (> 2000 m), time\|effective, and ability of avoiding near\|field disturbance due to its artificially generated energy, is usually applied to detecting the 3\|D variations of ore\|fracture belts in a great depths and orientation tendencies with relatively low resolution. EH4 system is, up to date, the most effective electromagnetic method for metalliferous mineral explorations with high detecting resolution and appropriate depths of penetration (800～1 200 m) . It is frequently used to investigate the spatial variations, sizes, detailed geometries of orebodies in mineralized/alteration zones. The disadvantage of EH4 system comes from its susceptibility to near-field disturbance which is required to be avoided or minimized to a lowest level during field data\|collecting. These three geophysical exploration methods were applied in combination in a case study at Chaihulanzi gold deposit in order to optimize exploration programs by maximizing the rate of ground coverage and minimizing the drilling requirement, which finally turn out an expected and ideal results in finding out a big extension of orebodies, both vertically and laterally.更多还原