The mining industry is a dynamic, exciting, and an amazingly diverse sector with more than 120 occupations ranging from skilled trades to high tech professionals.

If mining is an industry you are considering a career in, have you considered what it would be like to be a Geologist in mining?

Nicole Callaghan picture

Nicole Callaghan a Geologist in Alaska tells us all about her job.

By: Nicole Callaghan

“Most geologist that work for a mining company can be broken into two categories; production and exploration. These two areas, while both filled by geologists, are very different in day to day life.

For my first experience in the mining industry, I had the blessing to get an internship with an underground mine. This internship was not just the run of the mill internship that most companies offer, where they give you a simple job that you can’t screw up too badly and you do that job all day, every day for 8-12 weeks. For my internship, I had the opportunity to learn every geologist job that I could. I started at the bottom and worked my way through contractor tasks, exploration tasks, and production tasks. This offered me the complete picture of what, exactly, geologist really do in an underground mine and how the mining process works.

Here is just a little bit of what I learned.

It all starts with exploration. Exploration finds the ore that we are trying to mine. For the mine that I worked at, exploration was centered on underground diamond drilling. This drilling produced boxes of core, which offer a sliver of information about what the subsurface looks like. The length of these slivers can vary from hundreds to thousands of feet. The core goes first to the core loggers. In this job, I would go over every foot of core and determine mineralogy, rock name, collect angles of structures, and determine competency of the rock. This information is transposed onto a cross section, which are used to decide if the drill hole is on target and if other drill holes in the area may be necessary. I would then break the core into samples, based off of possible metal content. Once that is done, I followed the core down to the core cutters. Here, I would take a specific gravity of sections of the core that may contain metals, and then cut the core in half, placing half in a sample bag and half back in the box. The sample bags went to a lab, where they were assayed for metal content. Once done, this data is organized, entered into data bases, and used to produce 3D models of the ore deposit, categorized by grade of material and classification of rock. This is used to make a rough estimate of where the ore is in the mine, how much is there, and ultimately an estimate worth. The last part of this process is mainly office work, and does not involve any contact with the actual rocks, but rather just the data.

Production is the other side of the geology department. Production geologists focus on actually getting the ore out of the ground. It all begins with mine planning. Mine planning is an intricate dance between geologist, engineers, and mine managers. Basically the geologist say go in a squiggly line to get the ore out (probably), engineers say use this neat straight line, and mine managers say the equipment won’t do that. In the end, we end up with a combination of all three. Once a plan is in place, the next step is ore control. This is entirely on the geologist. I would visit active faces and muck piles, and sample them to determine the amount of metals present. This allows us to tell how much money we will make off a batch of rock, as well as what kind of waste it will be, which controls the location that it can be safely placed. If the results from a face showed that it was not economic to mine, then we would look at the 3D models of expected ore zone to decide if there may be ore nearby and if it would be worthwhile to continue the face. Next, I would map each face to track the path of the ore bands, and adjustment of mining path to accommodate changes in ore direction or ground conditions. I would also map drifts in order to decide it there are any ore locations in the ribs that need to be mined on the retreat, and to map any ore located above, below, and to the sides. This also maps structures to give an idea of the overall geology.

Exploration is centered more around the science of geology, looking at areas in detail (grain scale) and inferring a bigger picture. It is slower, based out of an office, and although you get to spend a lot of time with the rocks, it is with small slivers of the overall geology. Most of the things that you do will have an effect on the mine in the years scale, and while it offers the ability to form a plan for how the mine will proceed in the future, has minimal instantaneous feedback. You mainly work with just your immediate department and the drillers. The main every day workings of the mine are not a part of everyday life.

Production is faster paced and dirty. In my case, you spend most of your time underground (the dark and scary as it has been called to me), and you are handling the rock at the source. This allows you to look at the geology of the mine, such as seeing faults and folding as well as relationships between different lithology. You make decisions that have an effect on the day to day operations of the mine, and can see instant feedback from your choices. You are also working with a large variety of people from all sections of the mine, and are working with them to make the mine run. This is a higher stress job, where decisions that I made could be costly and possible dangerous if I chose wrong.

The field of geology is amazing because there are so many different jobs that can be filled by a geologist. The tasks that I did at my mine would change if it were a different type of deposit, or a different type of mine. Each job had its own skill set and purpose in the mine, and it is amazing how much team work goes into getting the ore out of the ground. I look forward to continuing in the geology community, trying new jobs, and learning everything I can about geology.”



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