- San Rafael Group
The San Rafael Group is a
geologic group of formations that is spread across theU.S. state s ofNew Mexico ,Arizona ,Utah andColorado . Part of theColorado Plateau , this group of formations was laid down in theMiddle Jurassic during theBajocian ,Bathonian andCallovian stages. [GEOLEX database] Asterisks (*) indicate usage by theU.S. Geological Survey .ubunits
Subunits (alphabetical): [GEOLEX database]
*Bell Ranch Formation (NM),
*Bluff Sandstone (AZ,NM),
*Carmel Formation (AZ*,CO*,NM*,UT*,WY*),
*Cow Springs Sandstone (AZ),
*Curtis Formation (CO*,UT*),
*Entrada Sandstone (AZ*,CO*,NM*,UT*),
*Henrieville Sandstone (UT),
*Page Sandstone (AZ*,UT*,WY*),
*Romana Sandstone (AZ*,UT*),
*Summerville Formation (AZ,CO,NM,UT),
*Temple Cap Sandstone (UT*) or Temple Cap Formation (UT),
*Thoreau Formation (NM),
*Todilto Limestone (AZ,CO*,UT*) or Todilto Formation (AZ,CO,NM,UT),
*Wanakah Formation (AZ*,CO*,NM*,UT*).History of investigation
There is no designated type locality for the group. It was named for exposures in the
San Rafael Swell inEmery County, Utah by Gilluly and Reeside in 1928. That same year they divided the group into (ascending): Carmel Formation, Entrada Sandstone (new), Curtis Formation (new), and Summerville Formation (new). Areal extent limits were established by Gregory and Moore in 1931. Smith in 1954 revised and divided the group into Entrada, Todilto, and Thoreau (new) formations in theSan Juan Basin . In 1959 another revision, this time by Griggs and Read, divided it into Entrada and Bell Ranch (new) formations in thePalo Duro Basin andSierra Grande Uplift . The Carmel-Navajo contact was revised by Wright and others in 1962 and the Carmel-Entrada contact was revised by Phoenix in 1963. Thompson and Stokes created an overview and named the Henrieville Sandstone in 1970. The Temple Cap Sandstone was revised and the Page Sandstone added (new) by Peterson and Pipiringos in 1979. A revision by O'Sullivan in 1980 divided the group into Carmel, Entrada, and Wanakah formations inParadox Basin . O'Sullivan revised the upper contact in 1984. In 1988 Peterson revised earlier work and divided the group into Page, Carmel, and Entrada formations in theBlack Mesa Basin ; divided it into Page, Carmel, Entrada and Romana (new) formations in thePlateau sedimentary province ; and divided it into Page, Carmel, Entrada, Curtis, and Summerville formations in Paradox Basin. Condon in 1989 revised the group inSan Juan Basin and divided it into Entrada and Wanakah formations in southeastern area; divided it into Entrada, Wanakah, and Cow Springs formations in south-central area; and divided it into Entrada and Cow Springs Sandstones in southwestern area. [For the whole section, except where noted: GEOLEX database Bibliographic References]Places found
Geologic Province: [GEOLEX database]
*Black Mesa Basin *
*Great Basin province*
*Palo Duro Basin *
*Paradox Basin *
*Piceance Basin *
*Plateau sedimentary province *
*San Juan Basin *
*Sierra Grande Uplift *Parklands (incomplete list):
*Canyonlands National Park - seegeology of the Canyonlands area
*Capitol Reef National Park - seegeology of the Capitol Reef area References
Works cited
* [http://ngmdb.usgs.gov/Geolex/NewUnits/unit_10460.html GEOLEX database entry for San Rafael Group] , USGS (viewed 20 March 2006)
* [http://ngmdb.usgs.gov/Geolex/NewRefsmry/sumry_10460.html GEOLEX database Bibliographic References for Glen Canyon] , USGS (viewed 20 March 2006)Notes
Wikimedia Foundation. 2010.