How Core Drilling Works
Core drilling is the systematic process of extracting core samples from a designated site using specially designed drills and equipment. It is often done fairly early in project development, as the data obtained can contribute to the validity and viability of a drilling or mining project. Drilling projects are cost-sensitive, making core drilling an invaluable tool for cost analysis.
Once a site is chosen, several holes are drilled at various on-site points to obtain a diverse sample selection and to create the most accurate representation of the site being surveyed. After conducting a thorough physical inspection of the site and the cores obtained from it, the cores (after being labelled and categorised) are sent to a laboratory for further analysis by a dedicated team of scientists and geologists.
What Can Core Samples Tell Us?
Core samples are cylindrical sections of rock and soil that can tell a lot about the physical and chemical composition of a site. The shape of a core sample is determined by the kind of drill that is used – core samples in particular are cylindrical, as the drill used is hollow to ensure that the sample maintains a specific shape (which makes it easier to analyse the various layers of rock at a site). If one were to blast a hole into the side of a mountain or into the ground, the result would be a mixture of rock and soil that is difficult to analyse and all but useless for a survey that specifically needs to analyse specific rock layers. Depending on the site being surveyed, a core sample may be densely packed with several layers (or strata) of different types of rock and soil, or it can seemingly be one solid, homogenous cylinder of rock. Whatever the actual core sample looks like, it can still provide valuable insight into the properties of a site.
The samples obtained from core drilling are mainly used to determine the mineral composition of a site. A mineralogical survey can thus indicate the presence of precious minerals (relevant to mining) and may provide insight into the structural composition and density of near-surface rocks (important for building surveys). Depending on where they were taken, core samples can also indicate the presence of aquifers (underground water reservoirs) and fossil beds.
The Role of Core Drilling And Geophysical Surveys in Mining
Geophysical surveys are in-depth studies conducted on a stretch of land to determine its potential uses. Most site inspections use a combination of survey techniques, including surface sample collection, aerial photography, seismology, remote sensing, and ground-penetrating radar. Because core drilling can provide stratified physical samples of a geographical location (as opposed to just photographs and radar imagery), it forms a key component in mineral exploration. Once each survey has been concluded and all the samples have been collected, the data is compiled and a comprehensive report is generated. A mining company may then use this report to justify a mining project to investors, adjust it according to financial or geological constraints, or completely scrap it.
Inyati Group specialises in mining exploration, geotechnical surveys, and drilling. For more information, contact us today.