| Ozan Formation | |
|---|---|
| Stratigraphic range: Cretaceous | |
 Fossil ammonites from the Ozan Formation | |
| Type | Formation |
| Sub-units | Austin Group |
| Underlies | Annona Chalk |
| Overlies | Austin Chalk, Brownstown Marl |
| Thickness | 150 to 250 feet [1] |
| Location | |
| Region | Arkansas, Oklahoma |
| Country | United States |
| Type section | |
| Named by | C.H. Dane [2] |
The Ozan Formation is a geologic formation in Arkansas, Oklahoma [1] and Texas. It preserves fossils dating back to the Cretaceous period.
The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller.
The Ulan Malgait Formation is a Late Jurassic geologic formation in Mongolia. Dinosaur remains are among the fossils that have been recovered from the formation, although as of 2004 none have yet been referred to a specific genus.
The Fayetteville Shale is a geologic formation of Mississippian age composed of tight shale within the Arkoma Basin of Arkansas and Oklahoma. It is named for the city of Fayetteville, Arkansas, and requires hydraulic fracturing to release the natural gas contained within.
The Trinity Group is a group in the Lower Cretaceous lithostratigraphy of Texas, Arkansas, Mississippi, Louisiana and Oklahoma. It is named for the Trinity River of Texas.
The Peedee Formation is a geologic formation in North and South Carolina. A marine deposit representing an inner neritic environment, named for exposures along the Great Peedee River, it preserves invertebrate and vertebrate fossils dating to the Late Cretaceous (Maastrichtian).
The Hale Formation is a geologic formation in northern Arkansas that dates to the Morrowan Series of the early Pennsylvanian. The Hale Formation has two named members: the Cane Hill and the Prairie Grove Members. The lower member is the Cane Hill, a primarily sandstone and shale interval that unconformably overlies the Mississippian-age Pitkin Formation. The upper member, the Prairie Grove Member, is predominately limestone and conformably underlies the Bloyd Formation.
The Moorefield Formation, or Moorefield Shale, is a geologic formation in northern Arkansas and eastern Oklahoma that dates to the Meramecian Series of the middle Mississippian. In Arkansas, this formation is generally recognized to have one member, the Ruddell Shale, in the upper Moorefield Formation.
The Bloyd Formation, or Bloyd Shale, is a geologic formation in Arkansas. It preserves fossils dating back to the Carboniferous period.
The Annona Chalk is a geologic formation in Arkansas, Texas, Louisiana, and Oklahoma. It preserves fossils dating back to the Cretaceous period. The formation is a hard, thick-bedded to massive, slightly fossiliferous chalk. It weathers white, but is blue-gray when freshly exposed. The unit is commercially mined for cement. Fossils in the Annona Chalk include coelenterates, echinoderms, annelids, bivalves, gastropods, cephalopods, and some vertebrate traces. The beds range in thickness, up to over 100 feet in depth in some areas ., but thins to the east and is only a few feet thick north of Columbus, Arkansas and is completely missing to the east. The break between the Annona Formation and the Ozan Formation appears to be sharp with a few tubular borings up to a foot long extending down from the Annona in to the Ozan.
The De Queen Formation, formerly known as the DeQueen Limestone Member is a Mesozoic geological formation located in southwestern Arkansas and southeastern Oklahoma in the United States. Fossil sauropod and theropod tracks have been reported from the formation. It preserves fossils dating back to the Cretaceous period, particularly the Albian age.
The Marlbrook Marl is a geologic formation in Arkansas. It preserves fossils dating back to the Late Cretaceous period.
The Saratoga Chalk is a geologic formation in Arkansas. It preserves fossils dating back to the Cretaceous period, specifically ammonites.
The Holly Creek Formation is a geologic formation in Arkansas. It preserves fossils dating back to the Cretaceous period which belong to the Trinity Group.
The Morrow Formation is a geologic formation from the Pennsylvanian geological age that is found in locations ranging from Southeast New Mexico and West Texas to locations in Oklahoma, Southwestern Kansas, and Arkansas. It preserves fossils dating back to the Carboniferous period.
The Goodland Limestone or Goodland Formation is a geologic formation in Arkansas and Texas. It preserves fossils dating back to the Cretaceous period.
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 Colorado City Formation is a Late Triassic geologic formation in the Dockum Group of Texas, United States. It has previously been known as the Iatan Member, Colorado City Member or 'Pre-Tecovas Horizon'.
The Gunsight Limestone Member is a geologic member in Texas. It preserves fossils.
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