GEOLOGIC MAP OF THE VERNAL NE 7.5' QUADRANGLE, UINTAH COUNTY, UTAH

Detailed 1:24,000-scale geologic mapping of the Vernal Northeast quadrangle is critical for understanding the complex transition zone between the northern Colorado Plateau, Uinta Basin, and the Laramide-age Uinta Mountains. This map addresses the need for current geological information in a rapidly developing urban and agricultural region by providing detailed stratigraphic and geomorphological characterization. A diverse set of methods were used to make this geologic map, integrating black-and-white stereographic aerial photographs from the mid-1900s with 1-meter light detection and ranging (lidar) data. I also incorporated a novel technique using relative elevation models derived from digital elevation models to more precisely map river terraces, enabling a more nuanced understanding of landscape evolution.

The Vernal NE Quadrangle map includes a stratigraphic sequence spanning from Upper Triassic/Lower Jurassic Nugget Sandstone to Holocene alluvial deposits. The quad contains multiple significant unconformities including the J-1 unconformity spanning approximately 14 million years and the K-0 unconformity spanning about 25 million years. Large-scale structures in the quad include synclinal and anticlinal folds, which are extensions of the Split Mountain anticline to the east in Dinosaur National Park. I examined numerous Quaternary pediment surfaces tied to erosion of the proximal Uinta mountains in addition to more recent strath terrace deposits, and even flood scouring from a June 1965 flood event. Potential geological hazards such as flooding and landslides were also identified. This map provides a comprehensive geological framework that enhances understanding of regional tectonic evolution, depositional environments, and landscape dynamics in this geologically complex transitional zone.