Analysis of a drill core through Mississippian rocks (Senior Independent Study Thesis by Michael Snader)
Mark Wilson April 19th, 2011
Editor’s note: Senior Independent Study (I.S.) is a year-long program at The College of Wooster in which each student completes a research project and thesis with a faculty mentor. We particularly enjoy I.S. in the Geology Department because there are so many cool things to do for both the faculty advisor and the student. We are now posting abstracts of each study as they become available. The following was written by Michael Snader, a senior geology major.
During Spring semester of 2010, I was given a core of the Black Hand Sandstone to study. The core was drilled just outside of Wooster, Ohio, but was originally drilled in search of oil, not for studying purposes. The Black Hand Sandstone is Mississippian (Osagean) in age and was named in 1915. The Black Hand Sandstone is distributed only throughout Ohio and is found mostly in central Ohio.
Once studying of the core began, I first had to cut the core in order to see the inner details. The core was roughly 65.8 meters long and had to be cut directly down the center. Cutting was done this way so that I could use one piece to study and make thin sections of, and leave the other piece as a record. Once cutting was done, I began looking through the core for a pattern to give me an idea of the paleoenvironment. As I studied the core, I found a series of hiatus concretions which I believe to be evidence of regressions. I also found crinoid fossils at various depths throughout the core which would be evidence of a deeper marine environment. There was a large section of shale near the bottom of the core that contained concretions as well. The concretions found within the sandstone and shale are both made of the same material and contain similar markings. Therefore, I propose that the concretions found in the sandstone represent regressions because they exist from an eroded shale layer. In conclusion, the concretions represent a series of regressions and show the depositional environment of the Black Hand Sandstone to be shallow marine.