| Mazarn Shale Stratigraphic range: Ordovician | |
|---|---|
| Type | Formation |
| Unit of | none |
| Sub-units | none |
| Underlies | Blakely Sandstone |
| Overlies | Crystal Mountain Sandstone |
| Thickness | 1000 to 2500+ feet [1] |
| Lithology | |
| Primary | Shale |
| Location | |
| Region | Arkansas, Oklahoma |
| Country | United States |
| Type section | |
| Named for | Mazarn Creek, Montgomery County, Arkansas |
| Named by | Hugh Dinsmore Miser [2] |
The Mazarn Shale is an Early Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. This interval was first described in 1892, [3] but remained unnamed until 1918 as part of a study by U.S. Geological Survey geologist Hugh Dinsmore Miser. [2]
The Mancos Shale or Mancos Group is a Late Cretaceous geologic formation of the Western United States.
The Powell Formation or Powell Dolomite is a geologic formation in northern Arkansas, southeast Missouri and Virginia. It contains gastropod, cephalopod, and trilobite fossils dating back to the Ordovician Period.
The Cotter Formation is a geologic formation in Arkansas, Missouri, Oklahoma and in Virginia. It preserves fossils dating back to the Ordovician period.
The Collier Shale is a geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. Dating from the Late Cambrian to Early Ordovician periods, the Collier Shale is the oldest stratigraphic unit exposed in Arkansas. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue assigned the type locality to the headwaters of Collier Creek in Montgomery County, Arkansas, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
The Hindsville Formation, or Hindsville Limestone Member of the Batesville Formation, is a geologic unit in northern Arkansas and eastern Oklahoma that dates to the Chesterian Series of the late Mississippian. Named for the town of Hindsville in Madison County, Arkansas, this unit is recognized as a member of the Batesville Formation in Arkansas and a geologic formation in Oklahoma. Although, some workers have proposed raising the rank of this interval in Arkansas to formation status. Both the Batesville and Hindsville Formations overlie the Moorefield Formation and underlie the Fayetteville Shale.
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 Dierks Limestone is a geologic formation in Arkansas. It preserves fossils dating back to the Cretaceous period.
The Crystal Mountain Sandstone is an Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. This interval was first described in 1892, but remained unnamed until 1909 as part of a study on the Ouachita Mountains of Arkansas by Albert Homer Purdue.
The Blakely Sandstone is a Middle Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue had initially named this unit the Caddo Shale at a 1907 Geological Society of America meeting, but later redefined and renamed the unit as the Ouachita Shale. He again renamed the unit to the Blakely Sandstone in a letter to Edward Oscar Ulrich, to which Ulrich used in a 1911 publication, becoming the first reference using this name. Ulrich assigned the Blakely Mountain in Garland County, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
The Womble Shale is a Middle Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas, where he named this unit as part of the upper Ouachita Shale and the Stringtown Shale. In 1918, U.S. Geological Survey geologist, Hugh Dinsmore Miser, replaced Purdue's nomenclature with the Womble Shale. Miser assigned the town of Womble in Montgomery County, Arkansas as the type locality. As of 2017, a reference section for this unit has yet to be designated.
The Bigfork Chert is a Middle to Late Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue assigned the town of Big Fork in Montgomery County, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated. The Bigfork Chert is known to produce planerite, turquoise, variscite, and wavellite minerals.
The Polk Creek Shale is a Late Ordovician geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue assigned Polk Creek in Montgomery County, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
The Blaylock Sandstone is a Silurian geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue assigned the Blaylock Mountain in Montgomery County, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
The Missouri Mountain Shale is a Silurian geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. First described in 1892, this unit was not named until 1909 by Albert Homer Purdue in his study of the Ouachita Mountains of Arkansas. Purdue assigned the Missouri Mountains in Polk and Montgomery counties, Arkansas as the type locality, but did not designate a stratotype. As of 2017, a reference section for this unit has yet to be designated.
The Stanley Shale, or Stanley Group, is a Mississippian stratigraphic unit in the Ouachita Mountains of Arkansas and Oklahoma. First described in Arkansas in 1892, this unit was not named until 1902 by J.A. Taff in his study of the Ouachita Mountains of Oklahoma. Taff assigned the town of Stanley in Pushmataha County, Oklahoma as the type locality, but did not designate a stratotype. After introduction into Arkansas in 1909 by Albert Homer Purdue, the unit was redefined in 1918, when the formation known as the Fork Mountain Slate was abandoned and partially combined into the Stanley Shale. As of 2017, a reference section for the Stanley Shale has yet to be designated.
The McAlester Formation is a Pennsylvanian geologic formation in the Ouachita Mountains of Arkansas and Oklahoma. Early descriptions of this unit considered it to be part of the Coal Measures, part of the Upper or Western Coal Bearing Division, the Spadra Stage and part of the Sebastian Stage, and part of the Cavaniol Group. In 1899, J.A. Taff introduced the McAlester Formation name in his study of the Ouachita Mountains of Oklahoma. The name was introduced into Arkansas in 1907 as the McAlester Group, where it consisted of the formations known as the Spadra Shale, the Fort Smith Formation, and the Paris Shale. These formations was redefined and replaced in 1960, when the McAlester Shale replaced the Spadra Shale and the lower Fort Smith Formation. The McAlester Formation is informally recognized with three sub-units in Arkansas: the Lower and Upper Hartshorne coal beds, and the McAlester coal bed. Taff assigned the type locality near the town of McAlester in Pittsburg County, Oklahoma, however he did not state whether the town is the origin of the name. Taff did not designate a stratotype and, as of 2017, a reference section for the McAlester Formation has not been designated.
The Lafferty Limestone is a Middle to Late Silurian geologic formation in the Ozark Plateaus of Arkansas. The name was introduced in 1921 by Hugh Dinsmore Miser in his study of Arkansas, replacing part of the upper St. Clair Limestone. Miser designated a type locality at Tate Spring, located 1.25 miles north of the site of the old Penters Bluff railroad station in Izard County, Arkansas, however, he did not assign a stratotype. As of 2017, a reference section has not been designated for this unit.
The Penters Chert is a Devonian geologic formation in the Ozark Plateaus of Arkansas. The name was introduced in 1921 by Hugh Dinsmore Miser in his study of Arkansas. Miser designated a type locality near the old Penters Bluff railroad station in Izard County, Arkansas, however, he did not assign a stratotype. As of 2017, a reference section has not been designated for this unit.
The Clifty Limestone is a Middle Devonian geologic formation in the Ozark Plateaus of Arkansas. The name was introduced in 1916 by Albert Homer Purdue and Hugh Dinsmore Miser in their study of northern Arkansas. They designated a stratotype along the East Fork of Little Clifty Creek in Benton County, Arkansas.
The Tokio Formation is a Late Cretaceous geologic formation in Arkansas and Oklahoma. Named in 1919 by Hugh Dinsmore Miser and Albert Homer Purdue in their study of Arkansas. They assigned the town of Tokio, Hempstead County, Arkansas as the type locality, but did not designate a stratotype for this unit.
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