Pictured Cliffs Sandstone
This unit is composed of primarily marine sandstone interbedded with thin layers of shale and is similar in composition, fossil assemblages, and depositional environment to the Intermediate unit of the Cliff House Sandstone. This unit is the youngest unit in the park and overlies the Lewis Shale. The Pictured Cliffs Sandstone represents the final regression of the Western Interior Seaway from northwestern New Mexico.
Did You Know?
On December 8, 1987, Chaco Culture National Historical Park was designated a UNESCO World Heritage Site, joining a select list of protected areas "whose outstanding natural and cultural resources form the common inheritance of all mankind" More...