U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Brainard shale*
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Shale
  • AAPG geologic province:
    • Iowa shelf
Publication:

Calvin, Samuel, 1906, Geology of Winneshiek County [Iowa], IN Wilder, F.A., and Savage, T.E., Annual Report, 1905, with accompanying papers: Iowa Geological Survey Annual Report, v. 16, p. 37-146.


Summary:

Pg. 60, 97. Brainard shale. Blue and bluish gray shales, with some intimately associated limestone beds at top and bottom. Thickness 120+/- feet. Forms top formation of Maquoketa stage [group]. Overlies Fort Atkinson limestone of Maquoketa stage and is succeeded by Hopkinton limestone of Niagara age. Age is Late Ordovician.
Named from exposures near Brainard, Fayette Co., northeastern IA.

Source: US geologic names lexicon (USGS Bull. 896, p. 249-250).


Map showing publication footprint
  • Usage in publication:
    • Brainard shale*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Iowa shelf
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. Brainard shale at Savannah, Illinois, is unconformably overlain by Burroughs dolomite.

Source: US geologic names lexicon (USGS Bull. 896, p. 249-250).


Map showing publication footprint
  • Usage in publication:
    • Brainard member*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Iowa shelf
Publication:

Twenhofel, W.H. (chairman), Bridge, Josiah, Cloud, P.E., Jr., Cooper, B.N., Cooper, G.A., Cumings, E.R., Cullison, J.S., Dunbar, C.O., Kay, Marshall, Liberty, B.A., McFarlan, A.C., Rodgers, John, Whittington, H.B., Wilson, A.E., and Wilson, C.W., Jr., 1954, Correlation of the Ordovician formations of North America: Geological Society of America Bulletin, v. 65, no. 3, p. 247-298., Ordovician Subcommittee of the Committee on Stratigraphy, of the National Research Council


Summary:

Chart 2 (column 59). Shown on correlation chart as Brainard member of Maquoketa formation. Underlies Neda shale member; Overlies Fort Atkinson limestone member.

Source: US geologic names lexicon (USGS Bull. 1200, p. 451).


Map showing publication footprint
  • Usage in publication:
    • Brainard member*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Iowa shelf
Publication:

Brown, C.E., and Whitlow, J.W., 1960, Geology of the Dubuque South quadrangle, Iowa-Illinois, IN Geology of parts of the Upper Mississippi Valley zinc-lead district: U.S. Geological Survey Bulletin, 1123-A, 93 p., (incl. geologic map, scale 1:24,000)


Summary:

Brainard member of Maquoketa shale. Described in Dubuque South quadrangle, Iowa-Illinois, where its rank is reduced to member status in Maquoketa shale. Consists of grayish-green and pale-blue soft dolomitic shale. Thickness as much as 135 feet. Underlies Neda member; overlies brown shaly unit in lower part of the Maquoketa.

Source: US geologic names lexicon (USGS Bull. 1200, p. 451).


Search archives

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

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

"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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 04 Apr 2024 04:19:52 PM MDT