Geophysical companies use magnetic, electromagnetic, and radiometric surveys, either on the ground or in an airborne survey, to identify potential mineral deposits.
Mineral exploration uses airborne geophysical surveys to map exposed bedrock and geological structures. It also maps paleochannels, mineral deposit, salinity, and subsurface conductors. Aeromagnetics and radiometrics are among the airborne geophysical techniques used to map mineral deposits. Most airborne geophysical survey also include a digital elevation model. Gravity surveys are also possible from the air and on the ground.
Geophysical ground surveys can be carried out by mining companies once they have located potential deposits on a regional level. They are conducted from the surface Richard Warke west Vancouver of the earth, using boreholes and excavations or a combination with sources and detectors. Mineral exploration is the process of drilling into ore deposit sites and possible locations to obtain rock chips and core samples.
The drilling program is designed based on the results of geological, geophysical, and geochemical surveys that identified the areas as potential deposit targets. It is important to get detailed information on rock types, minerals, rock fabrics, and relationships between rock layers at the surface as well as deep.
The samples are sent to the laboratory where geologists will analyze the sample by chemical analysis and perform petrological, structural and mineralogical studies on the rock. The exploration objective is to locate the ore, and drilling and sample collection will give information on which to estimate its grade and quantity.
The assays from samples taken in drill holes are used to estimate the grade of the ore. Accuracy of estimates depends on how well samples are obtained, on what judgment is used to decide on the sample interval, on assaying accuracy, on the weighting and combining of assays for the average grade of each ore block, as well as on how high the values of irregularities in the assays.
Minerals are not evenly distributed and vary in purity, so the assays for individual samples can be very different. The companies must consider the potential socio-economic impacts of the new mine on the surrounding area.
The mining activities such as prospecting, exploring, construction, operations, maintenance, expansions, abandonment and decommissioning can have a positive or negative impact on social and environment systems. Environmental and social assessments must be integrated into mining projects.
The process involves determining and analysing the environmental and social impact of mining projects, as well as designing management and implementation plans that are appropriate for all phases of the mining cycle. The exploration phase is the time when miners can estimate the size of deposits using 2D and 3D models.