Type locality, also called type area, is the locality where a particular rock type, stratigraphic unit or mineral species is first identified. If the stratigraphic unit in a locality is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality.
The term is similar to the term type site in archaeology or the term type specimen in biology.
Examples of geological type localities
Rocks and minerals
- Aragonite: Molina de Aragón, Guadalajara, Spain
- Autunite: Autun, France
- Benmoreite: Ben More (Mull), Scotland
- Blairmorite: Blairmore, Alberta, Canada
- Boninite: Bonin Islands, Japan
- Comendite: Comende, San Pietro Island, Sardinia
- Cummingtonite: Cummington, Massachusetts
- Dunite: Dun Mountain, New Zealand.
- Essexite: Essex County, Massachusetts, US
- Fayalite: Horta, Fayal Island, Azores, Portugal
- Harzburgite: Bad Harzburg, Germany
- Icelandite: Thingmuli (Þingmúli), Iceland
- Ijolite: Iivaara, Kuusamo, Finland
- Kimberlite: Kimberley, Northern Cape, South Africa
- Komatiite: Komati River, South Africa
- Labradorite: Paul’s Island, Labrador, Canada
- Lherzolite: Étang de Lers, France (Old spelling was: Étang de Lherz.)
- Mimetite: Treue Freundschaft Mine, Johanngeorgenstadt, Germany
- Mugearite: Mugeary, Skye, Scotland
- Mullite: Isle of Mull, Scotland
- Pantellerite: Pantelleria, off Sicily
- Portlandite: Scawt Hill, Ballygalley, Larne, County Antrim, Northern Ireland
- Rodingite: Roding River, New Zealand
- Sovite: Norsjø, Norway
- Strontianite: Strontian, Scotland (also the element strontium derived from the mineral)
- Temagamite: Copperfields Mine, Temagami, Ontario, Canada
- Tonalite: Tonale Pass
- Trondhjemite: Follstad, Støren, Norway
- Uraninite: Joachimsthal, Austria-Hungary (now Jáchymov, Czech Republic)
- Websterite: Webster in North Carolina.
- Widgiemoolthalite: Widgiemooltha, Western Australia, Australia
Formations
- Bearpaw Formation: Bear Paw Mountains, Montana, US
- Burgess Shale: Burgess Pass on Mount Burgess, Alberta–BC, Canada
- Calvert Formation: Calvert Cliffs State Park, Maryland, US
- Chapel Island Formation: Newfoundland, Canada
- Chattanooga Shale: Chattanooga, Tennessee, US
- Chazy Formation: Chazy, New York, US
- Fort Payne Formation: Fort Payne, Alabama, US
- Gault Formation: Copt Point, Folkestone, UK
- Ste. Genevieve Limestone: Ste. Genevieve, Missouri, US
- Upper Greensand Formation: Weald, Sussex, Hampshire
- Holston Formation: Holston River, Tennessee, US
- Jacobsville Sandstone: Jacobsville, Michigan, US
- St. Louis Limestone: St. Louis, Missouri, US
- Temple Butte Formation: Temple Butte, Grand Canyon, US
- Waulsortian_mudmound: Waulsort, Namur, Belgium