The Geology of the San Rafael Swell, Utah

Utah is home to beautiful landscapes and open expanses, creating popular vacation destinations and areas of research. The state has five national parks, the third-most in any state in the United States, including Arches, Bryce Canyon, Canyonlands, Capitol Reef, and Zion National Parks. But the beauty of these parks stem from the nature of the landscape, including the exposed rocks and underlying geology that helped create the landforms. Changing depositional environments, water levels, and erosional patterns helped form these geologic units, as well as the collision and movement of continental and oceanic crusts, active from over 500 million years ago to the present day. This report aims to explore the tectonic history of this region and further investigate the nature of the geologic units present, by utilizing descriptions of the rocks in both hand sample and outcrop, the nature of where these rocks outcrop (based on a geologic map) and finally, how the units are situated in the subsurface (based on a cross section).

In Spring of 2020, the COVID-19 pandemic struck, forcing schools and businesses to shut down, and classrooms to move online. DePauw University was one of these colleges that had to shut down its campus, causing most students to move back home and attend classes virtually. For the GEOS 220 course, Field Experiences: Utah, the course originally allowed for students to visit the San Rafael Swell in southeastern Utah. In Utah, strike and dip data, field observations, and geological interpretations would be recorded, and students would then create a geologic map, cross section, and stratigraphic column, before finally using this information to compile a report on Utah's geology. In light of the COVID-19 pandemic, this trip was cancelled. However, data collected during previous teachings of this course have allowed the same projects to be created, and this Story Map serves as a way to showcase those data and projects as a virtual report.

In southeastern Utah, the geologic units present in the San Rafael Swell and Moab areas provide evidence for the changing environments millions of years ago that formed the state's landscape visible today. Many of these units are exposed at National Parks such as Capitol Reef, Arches, and Canyonlands. The geology of the area includes a crystalline basement and Paleozoic rocks and evaporites that underlie the primary units: the Cutler, Kaibab, Moenkopi, Chinle, Wingate, Kayenta, Navajo, Carmel, Entrada, Curtis, Summersville, Morrison, Cedar Mountain, Dakota, and Mancos Formations. These units can be seen, along with ages and notable features, on the stratigraphic column of the area in Figure 5. The geology of this area shows changes of depositional history such as igneous and tectonic uplift activity, and environments of marine, fluvial, coastal, floodplain, alluvial, or eolian settings.

The following geologic map and cross section were created to provide a better understanding of the units present in the San Rafael Swell of southeastern Utah. The units discussed above are featured here, with their map symbols identified in the legend.