September 2024 UGA Luncheon

GEOLOGY OF BEARS EARS NATIONAL MONUMENT

Keilee Higgs, UGA President Elect

Bears Ears National Monument (BENM) covers a large area of southeastern Utah near the central Colorado Plateau, contains thousands of archeological and Native American cultural sites, and boasts exquisite geological scenery and valuable scientific and paleontological localities.The bedrock geology of Bears Ears ranges in age from about300 to 90 million years old,with a few much younger volcanics in the Abajo Mountains and to the south. Though the Colorado Plateau is a relatively rigid tectonic block of the western United States,these rocks demonstrate some unique structural deformation related to the Laramide Orogeny, manifested in the form of interesting faulting and folding patterns. The rocks in BENM have been a monumental puzzle of stratigraphic tangles and nomenclature issues that Keilee and Grant Willis(UGS, retired) have greatly enjoyed working through as they’ve prepared their chapter for the monument in the new 4th edition of UGA publication28, Geology of Utah’s Parks and Monuments, soon to be released. Keilee will discuss the geology of BENM and the unique issues of mapping such a large area of the Colorado Plateau while she shares her experiences working with and learning from Grant in the stunning vistas of the Monument.