At ONHYM, the main objective of mining exploration is to develop it and promote the country’s underground mining resources. The mining exploration process is divided into several stages during which different methods and techniques are used at various scales:

  • Remote sensing and hyperspectral

    Aware of the importance of remote sensing, ONHYM has been involved since 1986 in the theoretical and practical training of its teams.

  • Geophysics

    Geophysics has always been one of the exploration tools used within ONHYM...

  • Geochemistry

    A geochemical exploration campaign aims at locating economic mineral deposits through recognition of unusual concentrations of chemical components...

  • Geological prospecting

    For mineral exploration, The ONHYM’s Geologists use basic geological mapping is an absolute necessity...


Remote Sensing Airborne Geophysics Strategic Geochemistry Mapping at 1/100,000 - 1/50,000
Anomalies Map
Remote sensing Control Geophysics Control Detailed Geochemistry Lithogeochemistry Cartography at 1/10,000
Occurrences Inventory
Geophysics Control Detail Geochemistry Cartography at 1/2000 to 1/500 Strategic drilling (2 to 5) Summary Orientation Line Test
Prospects Inventory
Ore Extant Delimitations Retail drilling 3D Modelling Evaluation of calculated resources Structured line orientation study
Projects Inventory
Mining works Treatment tests Ealuation of measured resources Elaborating Promotional folder Pre-faisability Study
Assigned project or in ONHYM’s Portfolio
  • Processes

  • Regional Prospecting

    In areas where geological and mining data are scarce, a first phase of regional exploration (100 to 10,000 km²) called strategic is carried out to highlight anomalous areas. During this stage, essentially non-invasive techniques will be implemented both on the ground and in the airborne:

    • Remote sensing by satellite imagery / Hyperspectral
    • Airborne geophysics
    • Geological mapping
    • Regional geochemistry
  • Anomalies follow-up

    During this so-called tactical phase, the anomalies follow up in order to better understand their origin and their nature. In this anomaly control phase, non-invasive techniques comparable to those used in the previous exploration stage are used, but in a more detailed manner (10 to 100 km²).

  • Occurrences development

    During this qualified phase of occurrences development, superficial tools of the tactical phase (geochemistry and ground geophysics) are used, possibly in more detail, also investigations in the immediate subsoil (by trenches, by surveys or per well). This phase makes it possible to highlight prospects.

  • Prospect Evaluation

    During this phase, which aims to determine the envelope of the ore body and evaluate the resources, we mainly use boreholes and / or destructive holes, initially punctual (scattered) and then tightened systematically according to a regular grid with possibly measurements of the properties of the rocks traversed directly in sounding. This computerized data is used to generate 3D geological models that visualize the mineralized body envelope and its main characteristics.

  • Prospect development and promotion

    This phase consists of developing the prospect and promoting it through economic feasibility studies.