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Map showing publication footprint
  • Usage in publication:
    • Blackford facies
  • Modifications:
    • Named
  • Dominant lithology:
    • Shale
    • Dolomite
    • Limestone
  • AAPG geologic province:
    • Appalachian basin
Publication:

Butts, Charles, 1940, Geology of the Appalachian Valley in Virginia, Part 1: Virginia Geological Survey Bulletin, no. 52, 568 p.


Summary:

Named the Blackford facies of the Murfreesboro formation for Blackford, Russell Co., VA. The Blackford facies makes up the lower 70 feet or less of the Murfreesboro and consists of a heterogeneous sequence of red shale, red mottled argillaceous dolomite, gray shale, gray clay, and gray magnesian crumbly limestone. The basal bed is, in places, a massive layer or two, as much as 5 feet thick, of dull gray dolomitic rock containing many angular fragments of residual chert. The Blackford facies is of Middle Ordovician age.

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


Map showing publication footprint
  • Usage in publication:
    • Blackford member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin
Publication:

Cooper, B.N., and Prouty, C.E., 1943, Stratigraphy of the lower Middle Ordovician of Tazewell County, Virginia: Geological Society of America Bulletin, v. 54, no. 6, p. 819-886.


Summary:

The Blackford is revised as the Blackford member of the Cliffield formation in VA. Consists of basal clastics, ash gray shale, and blocky chert beds. Unit disconformably overlies the Beekmantown formation or the Five Oaks limestone member of the Cliffield formation.

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


Map showing publication footprint
  • Usage in publication:
    • Blackford formation
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Appalachian basin
Publication:

Prouty, C.E., 1946, Lower Middle Ordovician of southwest Virginia and northeast Tennessee: American Association of Petroleum Geologists Bulletin, v. 30, no. 7, p. 1140-1191. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Pg. 1145-1148. Blackford formation of Cliffield group. Geographically extended into northeastern Tennessee. [Age is Middle Ordovician.]

Source: US geologic names lexicon (USGS Bull. 1200, p. 362-363).


Map showing publication footprint
  • Usage in publication:
    • Blackford member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin
Publication:

Kay, Marshall, 1956, Ordovician limestones in the western anticlines of the Appalachians in West Virginia and Virginia northeast of the New River: Geological Society of America Bulletin, v. 67, no. 1, p. 55-106.


Summary:

Revised the Blackford as the Blackford member of the Lurich formation in western VA.

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


Map showing publication footprint
  • Usage in publication:
    • Blackford formation*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin
Publication:

Harris, L.D., and Miller, R.L., 1958, Geology of the Duffield quadrangle, Virginia: U.S. Geological Survey Geologic Quadrangle Map, GQ-111, scale 1:24,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_556.htm]


Summary:

Raised the Blackford to formation rank in VA. Consists of a basal unit (6 to 20 feet thick) of light gray to greenish gray lutite-textured dolomite containing angular chert fragments, a middle unit (about 60 feet thick) of interbedded calcareous shale, calcareous mudstone, and limestone, and upper unit (about 35 feet thick) of interbedded light gray lutite-textured limestone and light-gray calcareous shale. Unit overlies the Mascot dolomite and underlies the Elway limestone. The Blackford is of early Middle Ordovician age.

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


Map showing publication footprint
  • Usage in publication:
    • Blackford Formation
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin
Publication:

Ruppel, S.C., and Walker, K.R., 1984, Petrology and depositional history of a Middle Ordovician carbonate platform; Chickamauga Group, northeastern Tennessee: Geological Society of America Bulletin, v. 95, no. 5, p. 568-583.


Summary:

The Blackford Formation is revised to be included within the Chickamauga Group in eastern TN. It is the lowest most formation in the Chickamauga Group. Unit overlies the Knox Group and underlies the Five Oaks Formation of the Chickamauga Group. The Blackford is of Middle Ordovician age.

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


Map showing publication footprint
  • Usage in publication:
    • Blackford Member
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Appalachian basin

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

Ryder, R.T., Repetski, J.E., and Harris, A.G., 1996, Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian basin from Fayette County, Ohio, to Botetourt County, Virginia: U.S. Geological Survey Miscellaneous Investigations Series Map, I-2495.


Summary:

Geographically extended the Blackford Formation into the subsurface of WV on section F-F'. Unconformably overlies the Beekmantown Dolomite and underlies the Peery, Five Oaks, and Elway Limestones, undivided. The Blackford is of Middle Ordovician age.

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


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