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Geologic Unit: Bluff
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Map showing publication footprint
  • Usage in publication:
    • "Bluff sandstone"
  • Modifications:
    • Areal extent
  • Dominant lithology:
    • Sandstone
  • AAPG geologic province:
    • Paradox basin
Publication:

Baker, A.A., Dane, C.H., and Reeside, J.B., Jr., 1936, Correlation of the Jurassic formations of parts of Utah, Arizona, New Mexico and Colorado: U.S. Geological Survey Professional Paper, 183, 66 p.


Summary:

Pg. 21. "Bluff sandstone." At Bluff, San Juan County, southeastern Utah, the lower part of Morrison formation is composed of thin red and gray sandstone that forms cliffs along San Juan River and is locally known as "Bluff sandstone."

Source: US geologic names lexicon (USGS Bull. 896, p. 223).


Map showing publication footprint
  • Usage in publication:
    • Bluff sandstone member*
  • Modifications:
    • Principal reference
Publication:

Gregory, H.E., 1938, The San Juan country; a geographic and geologic reconnaissance of southeastern Utah, with contributions by M.R. Thorpe and H.D. Miser: U.S. Geological Survey Professional Paper, 188, 123 p.


Summary:

Pg. 58, pl. 15. Bluff sandstone member of Morrison formation. White to gray-brown, massive or thick-bedded, cross-bedded sandstone; in places thin-bedded; includes quartz aggregates, clay balls, and mudstones. Thickness 100(?) to 350 feet. Is basal member of Morrison formation. Underlies Recapture shale member (new); overlies Summerville(?) formation. Age is Late Jurassic.
Is outstanding topographic feature on both sides of the San Juan River at town of Bluff, San Juan Co., southeastern UT.

Source: US geologic names lexicons (USGS Bull. 896, p. 223; USGS Bull. 1200, p. 403-404).


Map showing publication footprint
  • Usage in publication:
    • Bluff sandstone member*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Paradox basin
Publication:

Map showing publication footprint
  • Usage in publication:
    • Bluff sandstone*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Black Mesa basin
    • Paradox basin
Publication:

Harshbarger, J.W., Repenning, C.A., and Irwin, J.H., 1957, Stratigraphy of the uppermost Triassic and the Jurassic rocks of the Navajo country: U.S. Geological Survey Professional Paper, 291, 74 p.


Summary:

Pg. 3 (fig. 2), 42-43, pls. 1, 3. Bluff sandstone of San Rafael group. In this report [Navajo country], Bluff sandstone believed to be tongue of Cow Springs sandstone, extending northward from main mass of Cow Springs, but, because of its homogeneous and mappable character and its areal extent (notably Mexican Water area, Arizona), it is considered a separate formation and assigned to upper part of San Rafael group. Ranges in thickness from few feet to about 300 feet. Age is Late Jurassic.

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 403-404).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone Member*
  • Modifications:
    • Revised
    • Areal extent
  • AAPG geologic province:
    • Paradox basin
    • Black Mesa basin
Publication:

O'Sullivan, R.B., 1980, Stratigraphic sections of Middle Jurassic San Rafael Group from Wilson arch to Bluff in southeastern Utah: U.S. Geological Survey Oil and Gas Investigations Chart, OC-102.


Summary:

Removed from San Rafael Group, reduced in stratigraphic rank from formation to member of Morrison Formation. Is recognized throughout southeast UT from north of Whiskers Draw and south of the Abajo Mountains where it tongues into the lower member of the Morrison, south to Bluff, San Juan Co in the Paradox basin. Is present south to Red Mesa and Garnet Ridge in northern Navajo and Apache Cos, AZ in the Black Mesa basin. Cross sections. Separated from the underlying Wanakah Formation of San Rafael Group by an unconformity. Coarse grains are abundant everywhere in basal part of the Bluff. Underlies Salt Wash Member of Morrison. Assigned to the Late Jurassic.

Source: GNU records (USGS DDS-6; Denver GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone Member*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Paradox basin
Publication:

O'Sullivan, R.B., 1984, The base of the Upper Jurassic Morrison Formation in east-central Utah: U.S. Geological Survey Bulletin, 1561, 17 p.


Summary:

In southeastern UT, between Monticello and Bluff, in the Paradox basin, Tidwell Member of Morrison Formation is replaced laterally by Bluff Sandstone Member. Is of Late Jurassic age.

Source: GNU records (USGS DDS-6; Denver GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone Member*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Black Mesa basin
Publication:

Condon, S.M., and Huffman, A.C., Jr., 1988, Revisions in nomenclature of Middle Jurassic Wanakah Formation, northwest New Mexico and northeast Arizona, IN Revisions to stratigraphic nomenclature of Jurassic and Cretaceous rocks of the Colorado Plateau: U.S. Geological Survey Bulletin, 1633-A, p. A1-A12.


Summary:

As the basal member of the Upper Jurassic Morrison Formation overlies Horse Mesa Member (new) of Wanakah Formation on northwest edge of study area at Toh Atin Mesa and Tsitah Wash, Apache Co, AZ, Black Mesa basin. Is a correlative of the B unit of the Junction Creek Sandstone. Name Bluff has been incorrectly applied in NM to older sandstone now known to be older than Bluff at Bluff, UT and separated from Bluff by an unconformity. Is a Paradox basin name not recognized in northwest NM.

Source: GNU records (USGS DDS-6; Denver GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone Member*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Paradox basin
Publication:

Peterson, Fred, 1988, Stratigraphy and nomenclature of Middle and Upper Jurassic rocks, western Colorado Plateau, Utah and Arizona, IN Revisions to stratigraphic nomenclature of Jurassic and Cretaceous rocks of the Colorado Plateau: U.S. Geological Survey Bulletin, 1633-B, p. B13-56.


Summary:

Cross-bedding dip vectors in Bluff Sandstone Member of Morrison Formation measured 5 km north of Bluff, San Juan Co, UT in Paradox basin, dip N 81 deg E suggesting that direction of cross-bedding dip provides a helpful method of distinguishing Cow Springs Member (new rank) of Entrada Sandstone from eolian sandstones of Morrison. Dip vectors in Cow Springs are southeast, south, southwest, and west. Of Late Jurassic age.

Source: GNU records (USGS DDS-6; Denver GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone
  • Modifications:
    • Not used
Publication:

Condon, S.M., 1989, Revisions of Middle Jurassic nomenclature in southeastern San Juan basin, New Mexico, IN Evolution of sedimentary basins; San Juan basin: U.S. Geological Survey Bulletin, 1808-E, p. E1-E21.


Summary:

Term Bluff Sandstone no longer used in the southeast part of the San Juan basin. The lower of two sandstones formerly assigned to the Bluff is named Mesita Member of Wanakah Formation. The upper of two sandstones formerly assigned to the Bluff is assigned as the eolian facies of the Recapture Member of the Morrison Formation.

Source: GNU records (USGS DDS-6; Denver GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Bluff Sandstone Member*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Paradox basin
    • Black Mesa basin
Publication:

Condon, S.M., 1989, Stratigraphic sections of the Middle Jurassic Wanakah Formation, Cow Springs Sandstone, and adjacent rocks, from Bluff, Utah, to Lupton, Arizona: U.S. Geological Survey Oil and Gas Investigations Chart, OC-131.


Summary:

Is the basal member of Upper Jurassic Morrison Formation. Shown as extending from Bluff, San Juan Co, UT in Paradox basin south beyond Tsitah Wash, Apache Co, AZ in Black Mesa basin. Pinches out in Apache Co, AZ west of Beclabito Dome, San Juan Co, NM.

Source: GNU records (USGS DDS-6; Denver GNULEX).


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Asterisk (*) indicates published by U.S. Geological Survey authors.

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