San Rafael Group

San Rafael Group
Stratigraphic range: Middle Jurassic
San Rafael Group on the east side of the San Rafael Swell. Entrada at the base, overlain by the Curtis, then Summerville, and capped by the Morrison (Tidwell and Salt Wash Members).
TypeGroup
UnderliesMorrison Formation
OverliesGlen Canyon Group
Thickness490 meters (1,610 ft)
Lithology
PrimarySandstone
OtherMudstone, limestone
Location
Coordinates39°10′26″N 110°27′58″W / 39.174°N 110.466°W / 39.174; -110.466
RegionFour Corners
CountryUnited States
Type section
Named forSan Rafael Reef
Named byGilluly and Reeside
Year defined1928
San Rafael Group is located in the United States
San Rafael Group
San Rafael Group (the United States)
San Rafael Group is located in Utah
San Rafael Group
San Rafael Group (Utah)
San Rafael Group strata exposed east of the San Rafael Swell, north of Hanksville. Sequence from orange cliff in foreground to cliff top in background Entrada Formation, Curtis Formation, Summerville Formation, capped by the (pink) Tidwell Member of the Morrison Formation.

The San Rafael Group is a geologic group or collection of related rock formations that is spread across the U.S. states of New Mexico, Arizona, Utah and Colorado. As part of the Colorado Plateau, this group of formations was laid down in the Middle Jurassic during the Bajocian, Bathonian and Callovian Stages.[1]

  1. ^ Ejembi, John I.; Potter-McIntyre, Sally L.; Sharman, Glenn R.; Smith, Tyson M.; Saylor, Joel E.; Hatfield, Kendall; Ferré, Eric C. (1 October 2021). "Detrital zircon geochronology and provenance of the Middle to Late Jurassic Paradox Basin and Central Colorado trough: Paleogeographic implications for southwestern Laurentia". Geosphere. 17 (5): 1494–1516. doi:10.1130/GES02264.1. ISSN 1553-040X.