Drilling allows rock samples to be taken from beneath the earth’s surface so that they can be analized for gold. It is the most expensive part of gold exploration, but is essential as it allows the delineation of a gold occurrence in 3 dimensions, rather than just 2 through surface sampling.
Before the decision is made to drill in a new area, there will have been positive results from previous exploration work such as soils, trenching or geophysics. These results are interpreted in the context of the local geology to give planned drill hole locations, orientation and depth.
The goal of any drill program is to find extensions of known gold bearing rock or new zones of gold bearing rock.
There are many types of drilling methods, though the two most common in gold exploration are diamond drilling and RC drilling. The decision to drill is a major one for small companies. The cost and time required to drill can be large especially in remote areas.