The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes. The Middle Jurassic San Rafael Group was dominantly deposited as ergs in a desert environment around the shallow Sundance Sea.
The Delaware Basin is a geologic depositional and structural basin in West Texas and southern New Mexico, famous for holding large oil fields and for a fossilized reef exposed at the surface. Guadalupe Mountains National Park and Carlsbad Caverns National Park protect part of the basin. It is part of the larger Permian Basin, itself contained within the Mid-Continent oil province.
The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch.
The Kaibab Limestone is a resistant cliff-forming, Permian geologic formation that crops out across the U.S. states of northern Arizona, southern Utah, east central Nevada and southeast California. It is also known as the Kaibab Formation in Arizona, Nevada, and Utah. The Kaibab Limestone forms the rim of the Grand Canyon. In the Big Maria Mountains, California, the Kaibab Limestone is highly metamorphosed and known as the Kaibab Marble.
Coconino Sandstone is a geologic formation named after its exposure in Coconino County, Arizona. This formation spreads across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah.
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah and Arizona. Specifically, the basin occupies space in the San Juan, Rio Arriba, Sandoval, and McKinley counties in New Mexico, and La Plata and Archuleta counties in Colorado. The basin extends roughly 100 miles (160 km) N-S and 90 miles (140 km) E-W.
The Summerville Formation is a geological formation in New Mexico, Colorado, and Utah of the Southwestern United States. It dates back to the Oxfordian stage of the Late Jurassic.
Cedar Mesa Sandstone is a sandstone member of the Cutler Formation, found in southeast Utah, southwest Colorado, northwest New Mexico, and northeast Arizona.
The San Andres Formation is a geologic formation found in New Mexico and Texas. It contains fossils characteristic of the late Leonardian (Kungurian) Age) of the Permian Period.
The Sandia Formation is a geologic formation in New Mexico, United States. Its fossil assemblage is characteristic of the early Pennsylvanian.
The El Cobre Canyon Formation is a geologic formation in New Mexico. It preserves fossils dating back to the late Pennsylvanian to early Permian periods.
The Abo Formation is a geologic formation in New Mexico. It contains fossils characteristic of the Cisuralian epoch of the Permian period.
The Manzano Group is a group of geologic formations in central New Mexico. These have radiometric ages of 1601 to 1662 million years (Ma), corresponding to the late Statherian period of the Paleoproterozoic.
The Yeso Group is a group of geologic formations in New Mexico. It contains fossils characteristic of the Kungurian Age of the early Permian Period.
The Atrasado Formation is a geologic formation in New Mexico. Its fossil assemblage dates the formation to the Kasimovian age of the Pennsylvanian. It was formerly known locally as the Wild Cow Formation or the Guadelupe Box Formation.
The Organ Rock Formation or Organ Rock Shale is a formation within the late Pennsylvanian to early Permian Cutler Group and is deposited across southeastern Utah, northwestern New Mexico, and northeastern Arizona. This formation notably outcrops around Canyonlands National Park, Natural Bridges National Monument, and Monument Valley of northeast Arizona, southern Utah. The age of the Organ Rock is constrained to the latter half of the Cisuralian epoch by age dates from overlying and underlying formations. Important early terrestrial vertebrate fossils have been recovered from this formation in northern Arizona, southern Utah, and northern New Mexico. These include the iconic Permian terrestrial fauna: Seymouria, Diadectes, Ophiacodon, and Dimetrodon. The fossil assemblage present suggests arid environmental conditions. This is corroborated with paleoclimate data indicative of global drying throughout the early Permian.
The Arroyo del Agua Formation is a geologic formation in New Mexico. It preserves fossils dating back to the early Permian period.
The Porvenir Formation is a geologic formation exposed in the southeastern Sangre de Cristo Mountains of New Mexico. It preserves fossils dating back to the middle Pennsylvanian period.
The Artesia Group is a group of geologic formations found in southeastern New Mexico and west Texas. These preserve fossils from the Leonardian to Guadalupian Epochs of the Permian Period.
The Victorio Peak Formation is a geologic formation found in the Delaware Basin in Texas and New Mexico. It preserves fossils dating back to the Leonardian Age of the Permian Period.
