The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
The McRae Group is a geological group exposed in southern New Mexico whose strata, including layers of the Hall Lake Formation and Jose Creek Formation, date to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from this unit.
The Sonyea Group is a geologic group in the northern part of the Appalachian Basin. It preserves fossils dating back to the Devonian period.
The Graford Formation is a geologic formation in Texas. It preserves fossils dating back to the Carboniferous period.
The Wolf Mountain Shale is a geologic formation in Texas. It preserves fossils dating back to the Carboniferous period.
The East Mountain Shale is a geologic formation in Texas. It preserves fossils dating back to the Carboniferous period.
The Arcadia Park Shale is a geologic formation within the Eagle Ford Group that outcrops in the northern portion of East Texas. It was deposited during the Middle to Late Turonian of the Late Cretaceous. It was originally described by W. L. Moreman from outcrops near the former Arcadia Park railway station west of downtown Dallas, where it is 100 ft thick. In the type area there is an unconformity between the Arcadia Park and the underlying Britton Formation. The base of the Arcadia Park is a thin limestone termed the Kamp Ranch Limestone. The Kamp Ranch Limestone is made up of broken pieces (prisms) of Inoceramus clams, and also contains shark's teeth. The remainder of the Arcadia Park in the Dallas area is shale with concretions. Sandstones are found within the Arcadia Park north of Dallas. The sandstones have been termed the Bells Sandstone Member for outcrops in Grayson County, and the Sub-Clarksville Sandstone in the subsurface. The shale overlying the Bells Sandstone has been named the Maribel Shale
The Lueders Formation is a geologic formation in Texas. It is the top formation of the Albany Group and preserves fossils dating back to the Permian period.
The Hueco Formation is a geologic formation in west Texas and southern New Mexico. It preserves fossils dating back to the early Permian period.
The Word Formation is a geologic formation in Texas. It preserves fossils dating back to the Permian period. It is probably named for the Old Word Ranch in the Glass Mountains of Brewster County.
The Gros Ventre Formation is a geologic formation in Wyoming, USA. It preserves fossils dating back to the Cambrian period. The Gros Ventre consists of three main members; the Wolsey Shale, the Death Canyon Limestone, and the Park Shale.
The Gray Mesa Formation is a geologic formation in New Mexico. Its fossil assemblage dates the formation to the Moscovian age of the Pennsylvanian.
The Wood Canyon Formation is a geologic formation in the northern Mojave Desert of Inyo County, California and Nye County and Clark County, Nevada.
The Claremont Shale is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.
The Mulholland Formation is a Pliocene epoch geologic formation in the Berkeley Hills and San Leandro Hills of the East Bay region of the San Francisco Bay Area, California. It is found within Alameda County and Contra Costa County.
The Plush Ranch Formation is a geologic formation in the Transverse Ranges of southern California. The formation preserves fossils dating back to the Late Oligocene to Early Miocene.
The Mint Canyon Formation (Tm) is a Miocene geologic formation in the Sierra Pelona Mountains of Los Angeles County, southern California. The formation preserves fossils dating back to the Middle to Late Miocene.
Texas 
United States 
