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National Geologic Map Database
Geologic Unit: Powell
Map showing publication footprint
  • Usage in publication:
    • Powell limestone*
  • Modifications:
    • Named
  • Dominant lithology:
    • Limestone
  • AAPG geologic province:
    • Ozark uplift
Publication:

Purdue, A.H., and Miser, H.D., 1916, Description of the Eureka Springs-Harrison quadrangle, Arkansas-Missouri: U.S. Geological Survey Geologic Atlas of the United States Folio, Eureka Springs-Harrison folio, no. 202, 22 p.


Summary:

Powell limestone was named by E.O. Ulrich (unpublished report) for Powell station, on White River branch of St. Louis, Iron Mountain, and Southern RR, where it is well exposed. Consists of light-gray to greenish-gray magnesian limestone with some shale and locally a bed of limestone conglomerate at base. Thickness is 0 to 200 ft. Unconformably underlies Everton limestone; unconformably overlies Cotter dolomite. [Age is Early Ordovician, Beekmantown.]

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


Map showing publication footprint
  • Usage in publication:
    • Powell Formation
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Ozark uplift
Publication:

Willman, H.B., Atherton, Elwood, Buschbach, T.C., Collinson, Charles, Frye, J.C., Hopkins, M.E., Lineback, J.A., and Simon, J.A., 1975, Handbook of Illinois stratigraphy: Illinois Geological Survey Bulletin, no. 95, 261 p.


Summary:

Shakopee Dolomite in IL is equivalent to Jefferson City and Cotter Dolomites of MO, and to the south may include strata equivalent to younger Powell and Smithville-Black Rock Formations.

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


Map showing publication footprint
  • Usage in publication:
    • Powell Dolomite
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Ozark uplift
Publication:

Nelson, W.J., 1996, Bedrock geology of the Paducah 1 degree x 2 degrees quadrangle, Illinois, Kentucky, and Missouri: Illinois Geological Survey Bulletin, no. 102, 40 p., (incl. geologic map, scale 1:100,000)


Summary:

Ordovician (Canadian) Powell, Smithville, and Black Rock Dolomites are recognized in southeastern MO by some geologists but not by others. The three formations, originally defined in AR, are generally mapped as an undivided unit on source maps. Smithville overlies and intertongues with Powell; Black Rock overlies and intertongues with Smithville.

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


Map showing publication footprint
  • Usage in publication:
    • Powell Dolomite*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Ozark uplift
Publication:

Harrison, R.W., 1997, Bedrock geologic map of the St. Louis 30' x 60' quadrangle, Missouri and Illinois: U.S. Geological Survey Miscellaneous Investigations Series Map, I-2533, 2 sheets, 7 p., scale 1:100,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_13024.htm]


Summary:

Powell Dolomite of Early Ordovician (Canadian) is present across entire St. Louis area. Shown separately in cross section only in MO and is not present in IL. In some places on geologic map, is included with either Cotter Dolomite or Jefferson City Dolomite. Contact with underlying Cotter is defined as unconformable in eastern MO.

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


Map showing publication footprint
  • Usage in publication:
    • Powell Dolomite*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Ozark uplift
Publication:

Nelson, W.J., 1998, Bedrock geology of the Paducah 1 degree x 2 degrees CUSMAP quadrangle, Illinois, Kentucky, and Missouri, IN The Paducah CUSMAP quadrangle, resource and topographical investigations: U.S. Geological Survey Bulletin, 2150-B, p. B1-B36, (incl. geologic map, scale 1:250,000), A joint study conducted with Illinois, Indiana, Kentucky, and Missouri geol. surveys [http://ngmdb.usgs.gov/Prodesc/proddesc_19757.htm]


Summary:

Ordovician (Canadian) Powell Dolomite crops out near western edge of Paducah quad. Jefferson City, Cotter, Powell, and Smithville Dolomites not mapped consistently between adjacent 7.5-minutes quads within Paducah quad. All consist of more or less silty, sandy, and cherty dolomite. Indistinguishable in subsurface except possibly through study of insoluble residues. Sequence is equivalent to Shakopee Dolomite in IL and KY.

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


Map showing publication footprint
  • Usage in publication:
    • Powell Dolomite*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Upper Mississippi embayment
    • Illinois basin
Publication:

Harrison, R.W., 1999, Geologic map of the Thebes quadrangle, Missouri and Illinois: U.S. Geological Survey Geologic Quadrangle Map, GQ-1779, scale 1:24,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_19294.htm]


Summary:

Early Ordovician (Canadian) Powell Dolomite mapped undivided with Smithville Dolomite in subsurface of Upper Mississippi embayment of MO and Illinois basin in IL.

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


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).