The method of geophysical prospecting is to measure the difference in the physical properties of underground rocks (ores) and infer the location, size and occurrence of the rocks (ores) underground, so as to achieve the purpose of indirect ore prospecting. The physical properties of surrounding rocks and ore bodies include resistivity, polarizability, magnetization, density, etc. Their numerical values can be obtained by measuring rock (mineral) stone specimens (outcrops) or borehole borehole logging. The greater the difference in physical properties between the surrounding rock and the ore body, the more effective the application of geophysical prospecting.
1.Resistivity parameter difference
Surrounding rocks such as breccia, dolomitic limestone and biotite granite have a resistivity of 1000～10000Ω·m, shale and marl have a resistivity of 100～1000Ω·m, while the resistivity of sphalerite is only About 100Ω·m, the resistivity is obviously different from that of the surrounding rock.
2.Polarizability parameter difference
The polarizability of marl, biotite granite, etc. are all less than 3.5%. The polarizability of the ore varies greatly depending on the content of the conductive material and the structure. However, as long as it is a dense ore, the polarizability is higher. The difference in polarizability of surrounding rock is also obvious.
The magnetization of biotite granite, marl and shale is relatively weak, which is more than ten times different from that of ore. It is an important indicator to distinguish between surrounding rock and ore body.
The density of ore is relatively high, and there is a density difference of 0.77g/cm3 from surrounding rocks such as biotite granite, which is an important indicator for effectively distinguishing surrounding rocks from ore bodies; the density of granite is very low, forming a low-density anomaly, and it is used to distinguish granite from rock formations. The location of the contact zone provides a basis for finding the ore-bearing site.