USGS Visual Identifier

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Geologic Unit: Benbolt

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.
Usage in Publication:
Benbolt limestone

Modifications: Geologic Province: Dominant Lithology:
 Named
 Appalachian basin
 Limestone

Summary:
Named the Benbolt limestone for Benbolt, Tazewell Co., southwestern VA. Consists of coarse-grained limestone, OPIKINA beds, CHASMATOPORA beds, and zone of cross-bedded limestone. The coarse-grained limestone and OPIKINA beds are called the Shannondale limestone member, the CHASMATOPORA and cross-bedded limestone are called the Burkes Garden limestone member. Maximum thickness of formation is 325 feet. Unit overlies the Cliffield formation and underlies the Gratton limestone. The Benbolt is probably correlative to the Lenoir limestone. The Benbolt is of Middle Ordovician age.
Source: GNU records (USGS DDS-6; Reston GNULEX).


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]
Usage in Publication:
Benbolt limestone

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Appalachian basin
 

Summary:
Geographically extended the Benbolt limestone to northeastern TN. Unit is well developed from Narrows VA, southwest to, and beyond, Heiskell, TN. Where the overlying Gratton limestone is absent, the Benbolt and Wardell formation cannot be separated lithologically. If a contact cannot be drawn between the Benbolt and Wardell, the combined units should be called Sevier formation.
Source: GNU records (USGS DDS-6; Reston GNULEX).


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.
Usage in Publication:
Benbolt Formation

Modifications: Geologic Province: Dominant Lithology:
 Revised
 Appalachian basin
 

Summary:
The Benbolt Formation is revised to be included within the Chickamauga Group in eastern TN. The Benbolt consists of predominantly nodular-weathering, yellow, argillaceous limestone to becomes entirely shale to the southeast. Thickness is about 100 meters in central part of study area. Unit overlies the Rockdell Formation and underlies the Wardell Formation, both of the Chickamauga Group. The Benbolt is of Middle Ordovician age.
Source: GNU records (USGS DDS-6; Reston GNULEX).


Publication:
Ryder, R.T., 1992, Stratigraphic framework of Cambrian and 
   Ordovician rocks in the central Appalachian basin from Morrow 
   County, Ohio, to Pendleton County, West Virginia, IN Evolution 
   of sedimentary basins; Appalachian basin: U.S. Geological 
   Survey Bulletin, 1839-G, p. G1-G25.
Usage in Publication:
Benbolt Limestone*

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Revised
 Appalachian basin
 

Summary:
In cross section E-E', extended into subsurface of WV in Pendleton Co. Replaces part of Big Valley Formation of Perry (1964).
Source: GNU records (USGS DDS-6; Reston GNULEX).