The Big Rock Formation is a formation that crops out in the Tusas Mountains of northern New Mexico. Detrital zircon geochronology gives a maximum age for the formation of 1665 Mya, corresponding to the Statherian period.
Exposure of Big Rock Formation at Mesa la Jara, New Mexico
Burned Mountain Formation
The Burned Mountain Formation is a geologic formation that crops out in the Tusas Mountains of northern New Mexico. It has a U-Pb radiometric age of 1700 Mya, corresponding to the Statherian period.
Burned Mountain Formation exposures near Placer Creek, New Mexico, USA
An outcrop of Burned Mountain Formation at Mesa la Jara, previously assigned to the Petaca Schist