Study of Amphiboles — Minerals that can Crystallize in the ‘Fibrous’ Habit and Potentially Create both Environmental and Health Concerns
Student: Alanna Schwanke
Advisor/Mentor: T. Diedrich
Minor: Environmental Science
Hometown: Two Harbors
Project Description: Last summer, I was an environmental intern at Northshore Mining in Silver Bay, Minnesota. While there, I performed the air sampling data around different areas of the plant. I also analyzed the reports from the laboratory where they measured elongated crystals/ crystal fragments that are referred to as ‘fibers.’ Throughout history, these fibers have created a great deal of controversy for Northshore Mining and have created both environmental and health concerns. The UROP project that I am pursuing follows directly from my internship experience.
The objectives of my UROP project are to: identify drill core from the Biwabik Iron Formation that had already been mined; analyze thin sections from the drill core to find where elongated fibrous minerals are present in the core; and to compare these minerals in the rock with those from historical air sampling data that was collected approximately when the rock was being mined. I researched drill core data from the Iron Range to identify an appropriate sample and visited the Minnesota Department of Natural Resources Core Repository in Hibbing. The sample chosen was from the previously mined Dunka River Pit. It was sampled every ten feet; the samples were made into thin sections, and were analyzed using optical microscopy. In the microscopy, I was able to see the various minerals in the ore. The group of minerals I was most interested in was amphiboles. These are the minerals that can crystallize in the ‘fibrous’ habit.
After seeing the crystallization habits of the amphibole group of minerals, I became interested in the air sampling data that was collected when the area where the drill core was located was mined. I then started comparing air sampling data to my thin section observations to see if there was any correlation between what was observed in the air and what was actually in the rock.
Why was I interested/ How do I feel about UROP?:
Since I spent a majority of my summer sampling the air around the plant and analyzing the ‘fiber’ length data, I became very interested in what exactly these elongated fragments of rock were. What did they look like, how did they get there, why are they so dangerous, and how exactly they became fibrous. I had heard that UMD was performing a study on these ‘fibers,’ so I asked around to see if I could answer some of my questions. That is when I ended up writing a research proposal to answer my questions.
This research experience has been incredibly interesting to me. I have learned an incredible amount of information. I asked many questions and eventually ended up writing a research proposal to attempt to answer my questions. Coming into the project, I had extremely limited knowledge of geology and thin section microscopy. I learned as I went and I am definitely still learning. So far, pursuing a UROP was a great decision and I would recommend it to everyone.
SCSE UROP Coordinator
Penny Morton, Assistant Dean
229 Heller Hall