Have you ever heard grown-ups say that the cars we drive are powered by dinosaurs? Yes, the original matter for oil is usually the tissue from living organisms. But in reality it might be algae buried 5 miles deep at the bottom of an ancient lake bed. How does this happen? Over time, the compaction of sediments forces surface soils down. At the beach, you can see the sandy sediments from rivers that were carried to the ocean. As time goes on, the weight of that beach deposit causes it to sink down, and as the rivers bring more sand, new layers form on top. This is called subsidence and compaction. Over millions of years many new layers accumulate.
Faulting also shifts surface layers downward. Mountain ranges all over the world, like the Colorado Rockies, are formed where part of the surface of the earth is cracked and pushed up. The areas next to the mountains are pushed down, burying sediment. Through 50 million years of geologic time, that same ancient lake bed by the edge of a mountain is now buried 20 or 30 thousand feet deep.
As the algae deposit gets deeper, it moves closer to the core of the earth. Here it is exposed to higher temperatures and weighted by the pressure of rock above it. This combination of heat and pressure “cooks” the ancient algal remains, leaving behind deposits of oil.
I work for an oil company to help find these deposits of oil in the Earth’s subsurface. We look at all the available data including geologic maps and well logs, which are geophysical readings of the rocks in a well that’s been drilled. Then we’ll create a seismic map by blasting dynamite. The sound from the explosion travels into the ground, and we can see how rocks are laid out by the reflection of the sound wave off the different rock types. It’s almost like an X-ray that you see at the hospital. Finally we take all that data and make a prediction on where we think the next deposit will be.
I found out about geology and geophysics when I worked at a coal mine for a summer just after of high school. We have one large mine on the Crow Indian reservation where I grew up, and others close by. Working with geoscientists, I was intrigued by their expertise in mapping the coal beds and predicting where they were underground. I was intrigued in their ability predict where the coal is going to be! When I learned that I could identify hidden deposits of oil and gas, even gold or silver or diamonds, I knew what I wanted to study.
Coming from an Indian school system, we’re not always prepared for the college level. I found a new and unfamiliar culture at Montana State University. That shock alone prevents many of us from continuing an education. Often the struggle is not about how smart you are, but how well you can cope with change, and how persistent you are. I started college dreaming only of a bachelor’s degree in geology. But by senior year, I realized that if I started working, my salary would not be what I was hoping for, so I got a master’s degree at Colorado School of Mines. Eventually I found myself saying, “Well, there are very few Natives with a Ph.D., why don’t you be the one who breaks the trail?”
My father was a tribal leader who ingrained in his children the understanding that a time would come when the tribe would need our specific skills, and we were obligated to come back and help. Five years ago I was called home. I shared my expertise of developing natural resources with the Crow and other tribes, and the steps for making informed decisions when dealing with outside companies. Whatever you choose, becoming a champion in your field will position you to be able to answer the call of your people when it comes.