Navajo Sandstone

The Navajo Sandstone is a geological formation within the Glen Canyon Group, composed of eolian, wind-deposited sandstone dating to the Early Jurassic, beginning around 200 to 195 million years ago based on 2019 radioisotopic analysis, spanning the Hettangian and Sinemurian stages. It accumulated in an ancient desert erg on the western part of the supercontinent Pangaea, where seasonal wind reversals came with annual monsoons each winter as cooler winds set in. The formation spans southern Nevada, northern Arizona, northwestern Colorado and Utah across the Colorado Plateau, reaching up to 2,300 feet, about 700 meters, thick, and its original sand sea is thought to have been substantially larger than the outcrops that survive today. It forms spectacular cliffs, cuestas, domes and bluffs, generally white in color though iron oxide alteration produces varied hues, and it contains hundreds of thousands of iron oxide concretions known as Moqui Marbles as well as preserved dinosaur track fossils. This entity documents the Navajo Sandstone specifically as a geological formation, an Early Jurassic eolian desert sedimentary deposit.