U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Eau Claire [sandstone]
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Sandstone
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Walcott, C.D., 1914, Cambrian geology and paleontology; No. 13, Dikelocephalus and other genera of the Dikelocephalinae: Smithsonian Miscellaneous Collections, v. 57, p. 345-412.


Summary:

Pg. 354. Eau Claire [sandstone]. (Ulrich mss. 1914). Mostly thin-bedded, in part shaly sandstone, with many fossiliferous layers, including Owen's Menominee trilobite zone and Wooster's Eau Claire trilobite zone. Usually a coarse white friable sandstone with DICELLOMUS and LINGULELLA at base. Numerous characteristic Upper Cambrian trilobites, CREPICEPHALUS IOWENSIS being one of best guide fossils. Thickness about 100 feet. Underlies Dresbach sandstone and overlies Mount Simon sandstone. Age is Late Cambrian.
[Named from exposures at mouth of Eau Claire River, near city of Eau Claire, Eau Claire Co., western WI.]

Source: US geologic names lexicon (USGS Bull. 896, p. 657-658).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire shale
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Ulrich, E.O., 1924, Notes on new names in table of formations and on physical evidence of breaks between Paleozoic systems in Wisconsin: Wisconsin Academy of Sciences, Arts and Letters, v. 21, p. 71-107.


Summary:

Pg. 71-93. Eau Claire shale, 200 to 350 feet thick, underlies Desbach sandstone and overlies Mount Simon sandstone in Wisconsin. Age is Late Cambrian.

Source: US geologic names lexicon (USGS Bull. 896, p. 657-658).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Trowbridge, A.C., and Atwater, G.I., 1934, Stratigraphic problems in the Upper Mississippi Valley: Geological Society of America Bulletin, v. 45, no. 1, p. 21-80.


Summary:

Eau Claire member of Dresbach formation. Treated these beds as a member of their Dresbach formation. Age is Late Cambrian.
[See 1934 and 1935 entries under Dresbach sandstone.]

Source: US geologic names lexicon (USGS Bull. 896, p. 657-658).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Twenhofel, W.H., Raasch, G.O., and Thwaites, F.T., 1935, Cambrian strata of Wisconsin: Geological Society of America Bulletin, v. 46, no. 11, p. 1687-1744.


Summary:

Pg. 1690, 1694. Eau Claire member of Dresbach formation. Middle member of Dresbach formation. Underlies Galesville member [Dresbach sandstone of many authors and reports] and overlies Mount Simon member. Divided, on basis of fossils, into CREPICEPHATUS zone (above), 75 feet thick, and CEDARIA zone (below), 50 feet thick. Coincides with "Eau Claire trilobite beds" of Wooster. Age is Late Cambrian.

Source: US geologic names lexicon (USGS Bull. 896, p. 657-658).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire sandstone*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Wilmarth, M.G., 1936, [Selected Geologic Names Committee remarks (ca. 1936) on Cambrian and Ordovician rocks of the U.S.], IN Wilmarth, M.G., 1938, Lexicon of geologic names of the United States (including Alaska): U.S. Geological Survey Bulletin, 896, pts. 1-2, 2396 p.


Summary:

Eau Claire sandstone. The USGS at present [ca. 1936] treats the Eau Claire as a distinct formation, underlying Desbach sandstone [Galesville member of some authors] and overlying Mount Simon sandstone. Age is Late Cambrian.
Named from exposures at mouth of Eau Claire River, near city of Eau Claire, Eau Claire Co., western WI.

Source: US geologic names lexicon (USGS Bull. 896, p. 657-658).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire member
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Iowa shelf
Publication:

Stauffer, C.R., and Thiel, G.A., 1941, The Paleozoic and related rocks of southeastern Minnesota: Minnesota Geological Survey Bulletin, no. 29, 261 p., (incl. geologic map)


Summary:

Pg. 30, 32, 33, measured sections. Eau Claire member of Dresbach formation. Middle member of Dresbach formation. Commonly medium- to fine-grained gray to buff sandstone with beds and partings of gray shale; may include conglomerates, and over large areas its shales may be red. Thickness about 128 feet at type section of Dresbach. Overlies Mount Simon member; underlies Galesville member. Present in southeastern Minnesota. Age is Late Cambrian.

Source: US geologic names lexicon (USGS Bull. 1200, p. 1209).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire sandstone*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Wisconsin arch
    • Iowa shelf
Publication:

Agnew, A.F., Behre, C.H., Jr., Heyl, A.V., Jr., and Lyons, E.J., 1956, Stratigraphy of Middle Ordovician rocks in the zinc-lead district of Wisconsin, Illinois, and Iowa [Mississippi Valley], IN Shorter contributions to general geology, 1955-57: U.S. Geological Survey Professional Paper, 274-K, p. K251-K312. [Available online from the USGS PubsWarehouse: http://pubs.er.usgs.gov/pubs/pp/pp274K]


Summary:

Pg. 255 (fig. 32), 371. Eau Claire sandstone. Referred to as Eau Claire sandstone. Overlies Mount Simon sandstone; underlies Dresbach sandstone. Thickness 70 to 330 feet. Age is Late Cambrian.

Source: US geologic names lexicon (USGS Bull. 1200, p. 1209).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire sandstone*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Wisconsin arch
    • Iowa shelf
Publication:

Keroher, G.C., 1960, [Selected U.S. Geologic Names Committee remarks, ca. 1960], IN Keroher, G.C., 1966, Lexicon of geologic names of the United States for 1936-1960: U.S. Geological Survey Bulletin, 1200, pts. 1-3, 4341 p.


Summary:

Eau Claire sandstone. USGS currently [ca. 1960] includes the Eau Claire sandstone in the Dresbach group. Present in western Wisconsin and southeastern Minnesota. Age is Late Cambrian.

Source: US geologic names lexicon (USGS Bull. 1200, p. 1209).


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Michigan basin
Publication:

Catacosinos, P.A., 1973, Cambrian lithostratigraphy of Michigan basin: American Association of Petroleum Geologists Bulletin, v. 57, no. 12, p. 2404-2418. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Munising retained at Formation rank north of line shown in fig. 8. In Upper Peninsula includes Miners Castle Sandstone and Chapel Rock Sandstone Members. In Lower Peninsula Munising raised to Group rank and includes Franconia Formation, Galesville Sandstone, and Eau Claire Formations.

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Michigan basin
Publication:

Lilienthal, R.T., 1974, Subsurface geology of Barry County, Michigan: Michigan Geological Survey Report of Investigations, no. 15, 36 p.


Summary:

In the subsurface of MI, the Munising Formation of the Lake Superior Group includes (descending) the Franconia Sandstone Member, the Dresbach Sandstone Member, the Eau Claire Member, and the Mount Simon Sandstone Member. Unit underlies the Trempealeau Formation of the Lake Superior Group and overlies the Jacobsville Sandstone. Age is Late Cambrian.

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation
  • Modifications:
    • Areal extent
    • Revised
  • AAPG geologic province:
    • Michigan basin
Publication:

Shaver, R.H., Ault, C.H., Burger, A.M., Carr, D.D., Droste, J.B., Eggert, D.L., Gray, H.H., Harper, Denver, Hasenmueller, N.R., Hasenmueller, W.A., Horowitz, A.S., Hutchison, H.C., Keith, B.D., Keller, S.J., Patton, J.B., Rexroad, C.B., and Wier, C.E., 1986, Compendium of rock-unit stratigraphy in Indiana; a revision: Indiana Geological Survey Bulletin, no. 59, 203 p.


Summary:

Munising extended to IN as Group within Potsdam Supergroup. In northwest IN, consists of the Franconia Formation (top), the Ironton Sandstone, the Galesville Sandstone, and the Eau Claire Formation. Unit includes only the Eau Claire in southwest IN, and only the Davis Formation (top) and the Eau Claire throughout most of the state. Underlies Potosi Dolomite and overlies Mount Simon Sandstone.

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Clayton, Lee, and Attig, J.W., 1990, Geology of Sauk County, Wisconsin; With a section about the Precambrian geology by B.A. Brown and an appendix naming the Rountree Formation by J.C. Knox, D.S. Leigh, and T.A. Frolking: Wisconsin Geological and Natural History Survey Information Circular, IC 67, 68 p., (incl. geologic map, scale 1:100,000)


Summary:

Eau Claire Formation of Elk Mound Group thins eastward onto the Wisconsin arch. Recognition difficult in south-central WI. Too thin in northeastern Sauk Co. to show on Plate 1 and so is mapped here with Wonewoc Formation. Known from drillhole cores in southeastern part of county. Unit that authors call Eau Claire in northeastern Sauk Co. consists of a few meters of reddish brown sandstone composed of very fine to coarse sand with some siltstone layers that are typically no more than a few mm thick. Coarser grains are primarily quartz and rounded. Characterized by thin flaggy bedding, commonly bioturbated and thin, dark reddish-brown layers, which consist of iron-oxide-cemented sandstone and cut across bedding. Poorly preserved fossil fragments present. Upper contact with Wonewoc not exposed; gradationally(?) overlies Mount Simon Formation. Unit probably 1 to 3 m thick in many parts of northeastern Sauk Co. Well logs in southeastern Sauk Co. indicate unit is between 50 and 100 m thick and consists of dolomitic sandstone composed of quartzose, very fine to medium sand with considerable dolomitic siltstone, dolomitic shale, and sandy dolomite. This strata referred to Eau Claire because they are roughly in the middle of the Elk Mound Group and because they resemble the Eau Claire of western WI.

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Michigan basin
Publication:

Catacosinos, P.A., and Daniels, P.A., Jr., 1991, Stratigraphy of Middle Proterozoic to Middle Ordovician formations of the Michigan basin, IN Catacosinos, P.A., and Daniels, P.A., Jr., eds., Early sedimentary evolution of the Michigan basin: Geological Society of America Special Paper, 256, p. 53-70.


Summary:

In the southern peninsula of MI, Eau Claire, Galesville, and Franconia Formations are collectively referred to the Munising Group because of their genetic relations. In the northern peninsula, Munising is retained at formation rank. This nomenclature follows Catacosinos (1973, 1974).

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Appalachian basin
Publication:

Ryder, R.T., Repetski, J.E., and Harris, A.G., 1997, Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian basin from Campbell County, Kentucky, to Tazewell County, Virginia: U.S. Geological Survey Miscellaneous Investigations Series Map, I-2530.


Summary:

Geographically extended the Eau Claire Formation into the subsurface of KY in the Cincinnati arch as shown in section G-G'. Overlies the Mount Simon Sandstone and underlies the Knox Group. Unit correlates with the Conasauga Formation in the Waverly arch and Ohio-West Virginia hinge zone of KY. The Eau Claire is of Late Cambrian age.

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


Map showing publication footprint
  • Usage in publication:
    • Eau Claire Formation*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Illinois basin
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:

Late Cambrian (Croixan) Eau Claire Formation consists of thin-bedded, shaly, fossiliferous sandstone overlying Mount Simon Sandstone in subsurface of IL and KY. Its facies equivalent, the Bonneterre Formation, consists of limestone and dolomite overlying Lamotte Sandstone on Ozark dome in MO.

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


Search archives

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 ([ ]).