Determining Depositional Environments using Paleomagnetic Data Collection

• Main Author: Kite, Joshua
• Format: Text
• Language: unknown
• Published: UWM Digital Commons 2019
• Subjects: North Pole
• Online Access: https://dc.uwm.edu/uwsurca/2019/Posters/80

Diamicts which are sediment that are unsorted to poorly sorted and contains particles ranging in size from clay to boulders, suspended in a matrix of mud or sand, can hold information about past landscapes and answer questions about what has happened in Earth’s past. This project attempts to determine how a diamict was deposited in a quarry in Northern Illinois. Was the diamict deposited sub-glacially, or by an underwater debris flow? This is important to determine since it will give us clues as to how far ancient glaciers had extended south from their origination near the north-pole and what the glacial activity did to the Earth’s landscape. I used magnetic techniques to determine the orientation of magnetic minerals in the diamict, which is related to flow direction during deposition. We can then relate it to the surrounding sand deposit data to determine if the diamict has a different flow direction. I was able to determine that the sand flow had a NE/SW direction, while the diamict had a W/NW direction which means that the deposit is sub-glacial since a debris flow would have had the same flow direction as the surrounding sand. Field observations confirmed this finding. Imbricated rock directions and the etched rocks on the bottom of the diamict showed signs of being dragged and scoured by the glacier. By determining how far the Ice stretched we can tell how much of the earth was covered with ice at any given point and also help to replace geologic time that could have been erased by the advancing glacier.