How does geology relate to mining?
Geology is the first step in mining and involves identifying prospective mineral deposits that might become mines. Geology also helps mine managers know where to develop once the mine is up and running.
Mining is part of what is known as the Mineral Resource Development Cycle - how to identify minerals, extract them, and cleanup mine sites for use by society. See the image below.
Geology plays a key role in the Exploration stage in finding mineral prospects that are of a high enough grade (the concentration of the mineral within an ore is referred to as its grade) to be economic and perhaps turned into a mine. But it takes something like a 100 mineral "showings" to find 1 prospect that is good enough to turn into a mine. This kind of geologist is called a "mineral exploration geologist."
Geology plays a role in the operational phase of a mine. Geologists must continually study the mineral deposit to guide mine engineers on the best way to develop the mine over time. This is called "mine geology".
Geologists might also play a role in the reclamation part of the cycle when the mine is closing. Reclamation is the process of restoring the area that was mined to its natural state or as close to its natural state as is feasible.