Overburden & Bedrock Mapping

Overburden and bedrock mapping or profiling is an essential in engineering, geotechnical or quarrying. On 2013, there are 356 quarries operates throughout this country. On 2014, it is estimated about 7,091 million metric tons of rock aggregates reserved available at in Malaysia (Jabatan Mineral dan Geosains Malaysia 2014).

Locating the bedrock is an essential for foundation and construction planning, geothermal energy extraction, groundwater in hard rock, mining or quarry. Geophysical technique can increases the accuracy of predicted excavation volumes or thickness and at the same time aiding in the determination of excavation and drilling sites.

Which Geophysical Method?

Electrical Resistivity Imaging (E.R.I) is a cost–effective non–destructive method for sand and gravel deposit assessment and quarry planning. This technique can provide 2D or 3D spatial models of the subsurface throughout the full region of interest. Hence, this complements intrusive sampling methods, which typically provide information only at discrete locations .

Seismic refraction survey also has good application in overburden and bedrock mapping or profiling. This technique measures the velocity properties of the earth materials at the project area. The velocity properties are useful to estimate the rippability prior to excavation of the overburden. This parameter is very crucial since it effecting the operation cost.

How These Geophysical Techniques Could Help?

Both electrical resistivity imaging and seismic refraction techniques will image the subsurface until the required depth. The product or result is presents in term of 2D profile.

Electrical Resistivity Imaging (E.R.I) can profile the thickness of the overburden and the depth of the bedrock trough the different electrical properties of these layers. From here,our client can have clearer image of the overburden and bedrock at the project area. Furthermore, the depth, thickness and continuity of the layers can be easily extracted from the E.R.I result.

Meanwhile, seismic refraction techniques also can image the thickness of the overburden and depth of the bedrock regarding their velocity properties. Each type of rock or earth materials have different velocities. In addition, from these velocities, our geophysicist can estimate the rippability of the earth materials at the project area.

Overburden and Bedrock Mapping or Profiling | Overburden thickness and depth of the bedrock can be estimated from the resistivity profile.
Seismic Refraction- Velocity profile | From the velocity, the rippability of the layer can be estimated

Who Need This?

  1. Quarry industry players
  2. Construction contractors
  3. Developers
  4. Engineering geologist
  5. Mining / Quarry engineer