Naturita Formation

The Naturita Formation is a sedimentary rock unit in Colorado made up of dark mudstones and siltstones interspersed with bands of sandstone. These layers record different depositional environments, from shallow marine settings to river systems, evident in the varying grain sizes and compositions.

The formation received its name in 1960 when geologist R.G. Young studied uranium deposits on the Colorado Plateau. This designation replaced an earlier classification as part of the Dakota Group and clarified the geological record of the region.

The formation holds fossils of early mammals, dinosaurs including ceratopsians and tyrannosaurids, plus plant remains from the Cretaceous Period.

The type locality near the former coal plant in Naturita offers the easiest access for viewing and studying the rock layers. It helps to visit during daylight hours and wear sturdy footwear, as the terrain can be uneven.

The rock layers reveal a complex network of Cretaceous coastlines and inland water systems that shifted multiple times through geological time. These patterns tell the story of an ancient landscape that repeatedly transformed between marine and freshwater conditions.

Location: Colorado

Made from material: mudstone

GPS coordinates: 37.60000,-112.90000

Latest update: December 14, 2025 16:41