The Pilar Formation is a geologic formation that crops out in the Picuris Mountains of northern New Mexico. It has a radiometric age of 1488 ± 6 million years, corresponding to the Calymmian period.
Pilar Formation carbonaceous phyllite beds near Pilar, New Mexico.
Pilar Formation exposures on Arroyo del Plomo
Outcrop of Pilar Formation showing metatuff beds (white layers)
Sample of carbonaceous phyllite from the Pilar Formation
The Rinconada Formation is a geologic formation that crops out in the Picuris Mountains of northern New Mexico. Detrital zircon geochronology establishes a maximum age for the Rinconada Formation of about 1723 Mya, placing it in the Statherian period of the Precambrian.
Rinconada Formation garnet-staurolite-muscovite schist beds near Pilar, New Mexico.
Crystals of staurolite weathered out of the Rinconada Formation, near Pilar, New Mexico.
Twinned staurolite from Rinconada Formation