Preliminary Report of Field Investigations in the Bryce Canyon National Park Area Conducted During the Summer of 1974

Lindquist, Robert

Bryce Canyon National Park is located on the eastern rim of the Paunsaugunt Plateau in southwestern Utah. The strata exposed here represent the most recent rocks of a continuous stratigraphy that can be traced fairly chronologically from the Pre-Cambrian at the bottom of the Grand Canyon, up through Zion National Park, and finally to Bryce Canyon. The main formations discussed are the Carmel, Entrada, Curtis, Windsor, Dakota, Tropic, Wahweap, Straight Cliffs, Kaiparowits, Wasatch, and Brian Head, in ascending order. Paleozoic deposits were controlled by the Cordilleran geosyncline to the west, and by the fluctuations of a shallow sea from the west. Early Mesozoic deposition was mainly terrestrial fresh water lacustrine and alluvial deposits which followed the regressing sea westward. The Sevier Orogeny shifted geosynclinal deposition into the area from the west, and orogenic movements caused folding, faulting, and supplied sediments to the area. These sediments were deposited in a shallow sea from the east. The final regression of this sea occurred in middle Cretaceous times. Uplift and erosion associated with the Laramide Orogeny followed, with volcanics being deposited throughout the Cenozoic era. Major faulting during the Pliocene epoch included the Sevier and Paunsaugunt faults which caused the present features of the area. Bryce Canyon is located on the fault block between these two north trending faults. Erosive forces took control of the landscape and are still modeling and reworking the fault blocks. The unique features found in Bryce Canyon National Park are a result of these erosive powers working on the Wasatch limestone.