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Geologic Unit: Alden
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Map showing publication footprint
  • Usage in publication:
    • Alden Pyrite Bed
  • Modifications:
    • Principal reference
  • Dominant lithology:
    • Shale
  • AAPG geologic province:
    • Appalachian basin
Publication:

Babcock, L.E., and Speyer, S.E., 1987, Enrolled trilobites from the Alden Pyrite Bed, Ledyard Shale (Middle Devonian) of western New York: Journal of Paleontology, v. 61, no. 3, p. 539-548.


Summary:

Alden Pyrite Bed herein formally named for exposures along Spring Creek, between Crittenden Rd and U.S. Rte 20, Alden, NY. Important stratigraphic marker characterized by conspicuous pyritic nodules and phacopine trilobites in band of dark-gray calcareous shale. Incorrectly described by Fisher (1951) as a "marcasite horizon." Thickness ranges up to 80 cm. At type section unit occurs 15.5 m below the top of the Ledyard Member of the Ludlowville Formation and 7.3 m below the "Athol Springs bed" of Kloc (1983). Lies between dark-gray crumbly to blocky shales above and calcareous, medium-gray shales below. Unit extends from Cazenovia Creek in Erie Co to Jaycox Run in Livingston Co, a distance of 80 km. Age is Middle Devonian (Givetian).

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


Map showing publication footprint
  • Usage in publication:
    • Alden pyrite interval
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin
Publication:

McCollum, L.B., 1991, Revised stratigraphy, sedimentology, and paleoecology of the Ledyard Member, Ludlowville Formation, New York, IN Landing, Ed, and Brett, C.E., eds., Dynamic stratigraphy and depositional environments of the Hamilton Group (Middle Devonian) in New York State, Part II: New York State Museum Bulletin, no. 469, p. 107-128.


Summary:

Alden pyrite interval occurs about 8 m above base of newly named Winspear submember [informal] of Ledyard Member of Ludlowville Formation. Unit is noted for its prized specimens of pyritized TORNOCERAS. Thickness about 1 m. (Name is credited to McCollum, 1980, SUNY PhD dissert.)
Notable exposures on Spring Creek, Alden Township, Erie Co., NY.
["Submember" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). Considered informal until formally published. The rank or lithologic term should not be capitalized.]

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


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 ([ ]).