Outcrop Mapping Using Unmanned Aerial Systems And Modeling Of The Shannon Sandstone In The Powder River Basin

Author

Emily Grace Sundell

Date of Award

January 2017

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Geology

First Advisor

Stephan Nordeng

Abstract

Mapping steep outcrops by hand is dangerous, time consuming and gathering images parallel to a cliff face is difficult to nearly impossible. Wyoming has many extensive, steep, surface outcrops that in the subsurface are petroleum-producing formations. The Powder River Basin (PRB) of Wyoming has been a prolific producer of petroleum since the late 1800s, and with continual advances in technology production continues to increase. During the Cretaceous, the PRB was inundated by the Western Interior Seaway. Sand-clay sequences corresponding to transgressions and regressions were deposited and resulted in the Campanian Shannon Member of the Cody Formation. The Shannon Member thickens to the west and thins to the east, but is still laterally extensive. In the western part of the basin, the Shannon Member has several surface exposures up to 36 m in thickness. These outcrops form steep cliffs of friable sandstone that pose safety risks for detailed close-up examination. Unmanned Aerial Systems (UAS) or drones allow for detailed imaging of the outcrops without risk to an individual.

Field research during the summer of 2017 was conducted in Natrona County, Wyoming. Images were collected using the DJI Phantom 4 Pro UAS. Image processing was performed using Agisoft PhotoScan and was concurrent with flight operations and continued into the fall. PhotoScan stitched images together to create 360Ð outcrop models. Three large outcrops were mapped and modeled successfully and are now in a three-dimensional digital model form.

Results show that drones are extremely useful tools for geologic mapping and in combination with image processing software can yield a product with many applications. This project produced high quality, georeferenced, 3D models of three outcrops of Shannon Sandstone Member. These models can be used to study outcrops without needing to be in the field. Studying the models allows for identification of sedimentary structures and facies changes. PhotoScan also has the ability to give exact geographical locations of outcrops and accurate measurements of outcrop features.

Recommended Citation

Sundell, Emily Grace, "Outcrop Mapping Using Unmanned Aerial Systems And Modeling Of The Shannon Sandstone In The Powder River Basin" (2017). Theses and Dissertations. 2359.
https://commons.und.edu/theses/2359