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Geologic Unit: Jensen
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Map showing publication footprint
  • Usage in publication:
    • Jensen Member
  • Modifications:
    • Named
  • Dominant lithology:
    • Siltstone
  • AAPG geologic province:
    • Great Basin province
Publication:

Arnold, C.A., and Sadlick, Walter, 1962, A Mississippian flora from northeastern Utah and its faunal and stratigraphic relations: University of Michigan, Museum of Paleontology Contributions, v. 17, no. 11, p. 241-263.


Summary:

Shown in correlation chart as uppermost member of Chainman Formation in Silver Island Range, western UT. [Chart shows composed of siltstone.] Overlies Willow Spring member (new) (Chainman Formation). Underlies Ely Limestone. Age shown as Mississippian and Pennsylvanian. "The Jensen and Willow Spring members will be introduced subsequently." p.251. [Note that Walter Sadlick (1966) later introduced Jensen member of Chainman Formation in PhD thesis (Dissertation Abstracts v.26 p.5978).]

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


Map showing publication footprint
  • Usage in publication:
    • Jensen Member
  • Modifications:
    • Areal extent
    • Biostratigraphic dating
  • AAPG geologic province:
    • Great Basin province
Publication:

Bissell, H.J., 1964, Ely, Arcturus, and Park City Groups (Pennsylvanian-Permian) in eastern Nevada and western Utah: American Association of Petroleum Geologists Bulletin, v. 48, no. 5, p. 565-636. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Measured section described on south face of west-trending spur in NE/4 sec.32 T17N R58E, White Pine Co, NV is 518 ft thick. "Jensen Member" of Chainman Shale is used in place of "Illipah Formation" (of old reports). Also shown in stratigraphic column as in Springer-Morrowan Series (CRAVENOCERAS SPP. and RHIPIDOMELLA NEVADENSIS Zones). Age given as Mississippian and Pennsylvanian.

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


Map showing publication footprint
  • Usage in publication:
    • Jensen Member
  • Modifications:
    • Age modified
    • Biostratigraphic dating
  • AAPG geologic province:
    • Great Basin province
Publication:

Sadlick, Walter, 1966, Biostratigraphy of the Chainman Formation (Carboniferous), eastern Nevada and western Utah: Dissertation Abstracts, v. 26, p. 5978.


Summary:

Jensen Member is uppermost member (of 6) of Chainman Formation along UT-NV boundary. Is an alluvial coastal plain and neritic facies. Thickness is about 450 ft. Lower part contains Namurian Zone of TUMULITES EUMORPHOCERAS YARIANS (late Chesterian) in which CRAVENOCERAS HESPERIUM is prolific. Uppermost part of unit contains RHIPIDOMELLA NEVADENSIS Zone. Age is Late Mississippian.

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


Map showing publication footprint
  • Usage in publication:
    • Jensen Member*
  • Modifications:
    • Mapped 1:24k
  • Dominant lithology:
    • Siltstone
    • Limestone
  • AAPG geologic province:
    • Great Basin province
Publication:

Hintze, L.F., 1986, Geologic map of the Mormon Gap and Tweedy Wash quadrangles, Millard County, Utah, and Lincoln and White Pine Counties, Nevada: U.S. Geological Survey Miscellaneous Field Studies Map, MF-1872, scale 1:24,000


Summary:

Is mapped as uppermost member (Chesterian) of Chainman Formation (Mississippian) in Mountain Home Range in western Millard Co, southwest UT (Great Basin province). Subdivisions of the Chainman mostly follow Sadlick (1965) with addition of two members [units] below his Needle Member. Sandberg and others (1980) have listed conodont zones using Sadlick's subdivisions. Overlies Willow Gap Limestone Member of Chainman (Chesterian). Overlain by Ely Limestone (Lower Permian, Pennsylvanian, and Upper Mississippian). Map unit described as thin-bedded calcareous siltstone and limestone that weathers reddish to yellowish brown; brachiopods, crinoid stems, blastoids, bryozoans and other fossils weather abundantly from some thin shaly limestone beds; includes a few thin quartzite beds; forms slopes and saddles between more resistant enclosing units; thickness ranges from 120 m in The Cove to 80 m on east flank of the Mountain Home Range.

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


Map showing publication footprint
  • Usage in publication:
    • Jensen Member*
  • Modifications:
    • Mapped 1:24k
  • Dominant lithology:
    • Siltstone
    • Limestone
  • AAPG geologic province:
    • Great Basin province
Publication:

Hintze, L.F., and Best, M.G., 1987, Geologic map of the Mountain Home Pass and Miller Wash quadrangles, Millard and Beaver Counties, Utah, and Lincoln County, Nevada: U.S. Geological Survey Miscellaneous Field Studies Map, MF-1950, 1 sheet, scale 1:24,000


Summary:

Is mapped as uppermost member (Chesterian) of Chainman Formation (Mississippian) in central part of Mountain Home Range in western Millard Co, southwest UT (Great Basin province). Subdivisions of the Chainman mostly follow Sadlick (1965, 1966) with addition of Delle Phosphatic Member (Sandberg and Gutschick, 1984) at base of formation. Sandberg and others (1980) have listed Chainman conodont zones using Sadlick's subdivisions. Overlies Willow Gap Limestone Member of Chainman (Chesterian). Overlain by Ely Limestone (Lower Permian, Pennsylvanian, and Upper Mississippian). Map unit described as thin-bedded calcareous siltstone and limestone that weathers reddish to yellowish brown; brachiopods, crinoid stems, blastoids, bryozoans and other fossils abundant in some thin shaly limestone interbeds; includes a few thin quartzite beds; forms slopes below more-resistant Ely Limestone; thickness 85 m in sec. 34, T25S, R19W.

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


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