Mineral Exploration

Malaysia is awarded with over 33 different mineral types, comprising metallic, non-metallic and energy minerals, worth several billion dollars in economic potential. Mineral exploration is one of profitable industry in this country. In 2016, the value of non-metallic mineral produced is estimated at RM5.05 billion, whilst the value of metallic and energy minerals produced is estimated at RM1.07 billion and RM0.16 billion, respectively.

The metallic mineral sub-sector produces minerals such as gold, tin, iron-ore, bauxite, ilmenite and other associated minerals. This associated minerals are by-products of tin and gold mining such as silver, zircon, monazite, rutile and struverite. The non-metallic or industrial mineral sub-sector produce sand, silica, limestone, clays, kaolin, gravel, aggregates, feldspar and mica. Only coal is produced in the energy mineral sub-sector.

Geophysics in mineral exploration involves quantitative measurements of response or contrast in properties between rocks, structures, stratigraphy and mineralization. Specifically, the variations are either on position of objects or function of time. Interpretation highlights signal “anomaly” of mineral-related features under investigation. Anomaly is significant departure from normal pattern of background values. It must be explained geologically indicating possible occurrences of mineral deposits. Moreover, geophysical technique is quick and cost-effective path to identify subsurface objects and prioritize drill targets.

Which Geophysical Method ?

Induced polarization (IP) is a geophysical method widely employed in mineral exploration especially in base-metals (metallic minerals) and gold exploration. The primary advantage of the IP method is its capability under favourable conditions to detect the presence of even small amounts of metallic minerals. The magnitude of IP response generally increases with the amount of mineralization up to the point where massive sulphide bodies can give large effects.

In addition, induced polarization is a particularly useful method in areas of disseminated mineralization where other geophysical exploration methods are much less effective.

How These Geophysical Techniques Could Help?

Theoretically, during the time of the original current flow, presumably some energy storage took place in the material. Laboratory studies of polarization in various rock types have established that chemical energy is the most important. The chemical energy storage is the result of

a)       variations in the mobility of ions in fluids throughout the rock structure.

b)      variations between ionic and electronic conductivity where metallic minerals are present.

The effect with presence of metallic minerals is known as electrode polarization or overvoltage. It is generally larger in magnitude than the background IP. Thus, the presence of metallic minerals is traceable by using IP technique.

Furthermore, after field data acquisition, the collected IP data (measurement) will be undergo inversion process to image the subsurface.  The product or result produced by the inversion process are present in coloured contour profile. The profile showing the variations in term of chargeability of the ground to depth. From here, our experienced geophysicist will interpret the prospect area or zone.

Induced Polarization (IP) profile for mineral exploration | Mineralized zone appear to be higher in chargeability values compared to the background values.

Who Need This ?

  1. Mining engineer
  2. Exploration geologist
  3. Mining industry player