Tonoloway Formation

Last updated
Tonoloway Formation
Stratigraphic range: Pridoli [1]
BlueRock2.JPG
A Tonoloway limestone "fin" known as Blue Rock, Smoke Hole Canyon, West Virginia
Typesedimentary
Underlies Keyser Formation
Overlies Wills Creek Formation
Thickness250+/-20 m
Lithology
Primary limestone
Other shale
Location
Region Appalachian Mountains
Extent Pennsylvania, Maryland, Virginia, West Virginia
Type section
Named forTonoloway Ridge, Rock Ford, WV
Named byE. O. Ulrich, 1911 [2]

The Late Silurian Tonoloway Formation is a mapped limestone bedrock unit in Pennsylvania, Maryland, Virginia and West Virginia. The Tonoloway is roughly equivalent to the Salina group that is found to the north and west.

Contents

Description

The basal 50 m consists of medium-dark-gray laminated to thin-bedded calcisiltite with shale partings and interbeds. Overlying 5 m are light-yellowish-gray to olive-gray mudstone and shale. Above this interval are 75 m of laminated calcisiltite with interbeds of thick to very thick bedded calcisiltite. The remainder of the formation is cyclic, consisting of three or four resistant ledges of laminated limestone and shale. Uppermost 20 m contains a variety of limestones. Lower contact with the Wills Creek is probably conformable. Upper contact is conformable and undulatory, occurring at the base of the "calico" limestone of the Keyser Formation. [3]

Depositional environment

The depositional environment of the Tonoloway is interpreted as shallow marine.

Notable exposures

Age

Relative age dating places the Tonoloway in the late Silurian.

Related Research Articles

<span class="mw-page-title-main">Shawangunk Formation</span> Bedrock unit in eastern Pennsylvania, New Jersey, and New York

The Silurian Shawangunk Formation is a mapped bedrock unit in eastern Pennsylvania, New Jersey, and New York. It is named for the Shawangunk Ridge for which it is the dominant rock type. The division of the Shawangunk between the Tuscarora Formation and Clinton Group has not been conclusively determined. The shift of nomenclature currently has the divide between Hawk Mountain and Lehigh Gap.

<span class="mw-page-title-main">Bloomsburg Formation</span>

The Silurian Bloomsburg Formation is a mapped bedrock unit in Pennsylvania, New Jersey, New York and Maryland. It is named for the town of Bloomsburg, Pennsylvania in which it was first described. The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin.

<span class="mw-page-title-main">Martinsburg Formation</span> Geologic formation in the eastern United States

The Ordovician Martinsburg Formation (Om) is a mapped bedrock unit in Pennsylvania, New Jersey, Maryland, Virginia, and West Virginia. It is named for the town of Martinsburg, West Virginia for which it was first described. It is the dominant rock formation of the Great Appalachian Valley in New Jersey (where it is called Kittatinny Valley and Pennsylvania.

<span class="mw-page-title-main">Tuscarora Sandstone</span> Bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, USA

The Silurian Tuscarora Formation — also known as Tuscarora Sandstone or Tuscarora Quartzite — is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, USA.

<span class="mw-page-title-main">Juniata Formation</span>

The Ordovician Juniata Formation is a mapped bedrock unit in Pennsylvania and Maryland. It is a relative slope-former occurring between the two prominent ridge-forming sandstone units: the Tuscarora Formation and the Bald Eagle Formation in the Appalachian Mountains.

<span class="mw-page-title-main">Reedsville Formation</span> Rock formation in the USA

The Ordovician Reedsville Formation is a mapped surficial bedrock unit in Pennsylvania, Maryland, Virginia, West Virginia, and Tennessee, that extends into the subsurface of Ohio. This rock is a slope-former adjacent to the prominent ridge-forming Bald Eagle sandstone unit in the Appalachian Mountains. It is often abbreviated Or on geologic maps.

<span class="mw-page-title-main">Clinton Group</span> Lithostratigraphic unit

The Clinton Group is a mapped unit of sedimentary rock found throughout eastern North America. The interval was first defined by the geologist Lardner Vanuxem, who derived the name from the village of Clinton in Oneida County, New York where several well exposed outcrops of these strata can be found. The Clinton Group and its lateral equivalents extend throughout much of the Appalachian Foreland Basin, a major structural and depositional province extending from New York to Alabama. The term has been employed in Kentucky, Maryland, Michigan, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia, though in many of these areas the same interval is referred to as the Rose Hill, Rockwood, or Red Mountain Formations. Historically the term "Clinton" has also been assigned to several lower Silurian stratigraphic units in Ohio and Kentucky which are now known to be significantly older than the Clinton Group as it was originally defined. Many parts of this succession are richly fossiliferous, making the Clinton Group an important record of marine life during the early Silurian. Several economically valuable rock-types are found within this interval, though it is perhaps best known as a significant source of iron ore

The Silurian McKenzie Formation is a mapped bedrock unit in Maryland.

<span class="mw-page-title-main">Wills Creek Formation</span> Bedrock unit in the Eastern United States

Wills Creek Formation is a mapped Silurian bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia.

<span class="mw-page-title-main">Hamilton Group</span> Geological Group in North America

The Hamilton Group is a Devonian-age geological group in the Appalachian region of the United States. It is present in New York, Pennsylvania, Maryland, Ohio, West Virginia, northwestern Virginia and Ontario, Canada. It is mainly composed of marine shale with some sandstone. There are two main formations encompassed by the group: the Mahantango Formation and the Marcellus Shale. In southwestern Virginia, where the two sub-units are not easily distinguishable, the Hamilton Group is broadly equivalent to the Millboro Shale or Millboro Formation. The group is named for the village of Hamilton, New York. These rocks are the oldest strata of the Devonian gas shale sequence.

The Devonian Mahantango Formation is a mapped bedrock unit in Pennsylvania, West Virginia, and Maryland. It is named for the North branch of the Mahantango Creek in Perry and Juniata counties in Pennsylvania. It is a member of the Hamilton Group, along with the underlying the Marcellus Formation Shale. South of Tuscarora Mountain in south central Pennsylvania, the lower members of this unit were also mapped as the Montebello Formation. Details of the type section and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database.

The Mississippian Mauch Chunk Formation is a mapped bedrock unit in Pennsylvania, Maryland, and West Virginia. It is named for the township of Mauch Chunk, now known as borough of Jim Thorpe, Pennsylvania and for nearby Mauch Chunk Ridge where the formation crops out.

<span class="mw-page-title-main">Marcellus Formation</span> Middle Devonian age unit of sedimentary rock

The Marcellus Formation or the Marcellus Shale is a Middle Devonian age unit of sedimentary rock found in eastern North America. Named for a distinctive outcrop near the village of Marcellus, New York, in the United States, it extends throughout much of the Appalachian Basin.

The Debolt Formation is a stratigraphical unit of Meramecian age in the Western Canadian Sedimentary Basin.

<span class="mw-page-title-main">Old Port Formation</span>

The Devonian Old Port Formation is a mapped bedrock unit in Pennsylvania, USA. Details of the type section and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. Current nomenclature usage by U.S. Geological Survey restricts the name Old Port Formation to Pennsylvania, but correlative units are present in adjacent states.

<span class="mw-page-title-main">Keyser Formation</span>

The Late Silurian to Early Devonian Keyser Formation is a mapped limestone bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia.

<span class="mw-page-title-main">Tomstown Dolomite</span>

The Tomstown Dolomite or Tomstown Formation is a geologic formation in Maryland, Pennsylvania, Virginia and West Virginia. It preserves fossils dating to the Cambrian Period.

The Waynesboro Formation is a limestone, dolomite, and sandstone geologic formation in Virginia, Maryland, Pennsylvania and West Virginia. In some areas it is composed of limestone and dolomite. The Waynsboro Formation is one of the formations that make up the Shenandoah Valley. It dates back to the Cambrian period and is not considered fossiliferous.

The Bertie Group or Bertie Limestone, also referred to as the Bertie Dolomite and the Bertie Formation, is an upper Silurian geologic group and Lagerstätte in southern Ontario, Canada, and western New York State, United States. Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. The formation comprises dolomites, limestones and shales and reaches a thickness of 495 feet (151 m) in the subsurface, while in outcrop the group can be 60 feet (18 m) thick.

References

  1. Paleozoic Sedimentary Successions of the Virginia Valley & Ridge and Plateau
  2. Ulrich, E.O., 1911, Revision of the Paleozoic systems: Geological Society of America Bulletin, v. 22, p. 281-680.
  3. Faill, R.T., Glover, A.D., and Way, J.H., 1989, Geology and mineral resources of the Blandburg, Tipton, Altoona, and Bellwood quadrangles, Blair, Cambria, Clearfield and Centre Counties, Pennsylvania: Pennsylvania Geological Survey Topographic and Geologic Atlas, 4th series, 86, 209 p., scale 1:24,000 and 1:48,000