Grand Canyon-Parashant is located at the junction of two major physiographic provinces, the Colorado Plateau and Basin and Range. Sedimentary rock layers are relatively undeformed and unobscured by vegetation. Deep canyons, mountains, and lonely buttes testify to the power of geologic forces. Geologic faults range from over 6 million years to much newer faults of only 30,000 years. Fossils are abundant on the monument. Among these are large numbers of invertebrate fossils and sponges swallowed up by the muddy bottom of a shallow ancient sea.
The western portion of Grand Canyon-Parashant National Monument is where Basin and Range meets Colorado Plateau. It is a dynamic geologic environment with stunning vistas and mountains on the move.
Presidential Proclamation No. 7265 that created Grand Canyon-Parashant National Monument notes that …”the Monument is a geological treasure…sedimentary rock layers are relatively undeformed and unobscured by vegetation, offering a clear view to understanding the geologic history…these cliffs…form a spectacular boundary between the Basin and Range and the Colorado Plateau geologic provinces…the Plateau here is capped by volcanic rocks...pocketed with sinkholes and breccia pipes...fossils are abundant in the monument.” (Clinton 2000).
The following sections will set the stage for readers explaining the processes that created the world-class landscape people can enjoy today.
Section 1: A Boundary Between Geologic Provinces
Section 2: Plate Tectonics
Section 3: Geologic Evolution of the Monument over the last 600 million years
Breccia Pipes Mining in the Grand Canyon and on the Arizona Strip
(NEW!) Interactive Geologic Map of the Grand Canyon (University of Arizona)
Mt. Trumbull Geologic Quadrangle Map (Billingsley)
Mt. Trumbull Geologic Quadrangle Summary of the quadrangle (Billingsley)
Littlefield, AZ (Grand Wash/Western GC-Parashant) Quadrangle Map and Pamphlet (Billingsley)
Hat Knoll (just north of Mt. Trumbull) Geologic Report (Billingsley)
Lower Grand Wash (Pakoon Basin/Tassi/Pakoon area) Geologic Report (Billingsley)
Please contact us using the link at the bottom of the page if you would like to be emailed Parashant's Geology Road Guide to the Pakoon Basin. (There are issues uploading the PDFs to this website)
Follow this link for a deep dive into the monument's amazing volcanic history of Parashant.
