Age and History of Investigation
This formation has been dated to the early to middle Callovian stage of the latest Middle Jurassic. The type locality and place for which the unit is named is Entrada Point, located in the northern part the San Rafael Swell in Emery County, Utah.
Entrada Sandstone was named as one of the four formations of the San Rafael Group by Gilluly and Reeside in 1928. Gregory and Moore worked out the geographic extent of the formation and gave an overview of it in 1931. The extent was revised several times afterwards (most recently in 1992 by Condon). It was divided into Gunsight Butte, Cannonville, and Escalante members by Thompson and Stokes in 1970. The principal reference for the formation was written in 1988 by Peterson.
Read more about this topic: Entrada Sandstone
Famous quotes containing the words age and/or history:
“To tell the truth, I saw an advertisement for able-bodied seamen, when I was a boy, sauntering in my native port, and as soon as I came of age I embarked.”
—Henry David Thoreau (1817–1862)
“The reverence for the Scriptures is an element of civilization, for thus has the history of the world been preserved, and is preserved.”
—Ralph Waldo Emerson (1803–1882)