The Middle Jurassic Entrada Sandstone in northeastern Arizona and adjacent areas
Robert B. O'Sullivan

Abstract:

In northeastern Arizona the Entrada Sandstone is about 30 m thick and consists of upper and lower sandy members and a middle silty Rehoboth Member. The Middle Jurassic Carmel and Wanakah Formations underlie and overlie the Entrada respectively. Locally, the formation directly overlies the Lower Jurassic Glen Canyon Group. The basal sandstone member and equivalent units form a narrow arcuate band stretching from west-central New Mexico through northeast Arizona and into southeastern Utah and southwestern Colorado. The overlying Rehoboth Member extends as much as 100-150 km eastward over the lower member. The upper sandy member is thicker and widespread in New Mexico and is equivalent in part to the Slick Rock Member in southwest Colorado. The stratigraphy and nomenclature of the Entrada and associated strata have been subjected to different interpretations.


Citation:

  1. O'Sullivan, Robert B., 2003, The Middle Jurassic Entrada Sandstone in northeastern Arizona and adjacent areas, in: Geology of the Zuni Plateau, Lucas, Spencer G.; Semken, Steven C.; Berglof, William R.; Ulmer-Scholle, Dana S., New Mexico Geological Society, Guidebook, 54th Field Conference, pp. 303-308.

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