Breathitt Formation is informally elevated to group rank and subdivided into the following eight informal formations: Pocahontas, Bottom Creek, Alvy Creek, Grundy, Pikeville, Hyden, Four Corners, and Princess formations. Bottom Creek formation includes the Cumberland Gap coal bed and the Dark Ridge Member, reassigned from the Lee Formation. [Revisions made in this paper are strongly contested by C. Rice and other USGS scientists who work in this area (oral commun., 9/3/93).]

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

The informal Bottom Creek formation of Breathitt Group, named for Bottom Creek in Keystone quad, WV, is composed of typical non-quartzose Breathitt lithologies--interbedded argillaceous and lithic sandstone, siltstone, shale, and coal. Reaches a maximum thickness of 300 m. It occurs mainly in WV and VA, but is present in KY along Cumberland Mountain, where it is represented by the Dark Ridge Member. Overlies Warren Point Sandstone of Breathitt Group, or the Pocahontas No. 8 coal. Underlies Sewanee Sandstone, also of Breathitt Group, or the Upper Seaboard coal. Toward the northwest, the Bottom Creek is interbedded and eventually replaced by the Warren Point-Sewanee Sandstones. Unit is equivalent to the lower half of the New River Formation, and the Signal Point Shale and the lower part of the Fentress Shale of TN. According to the author, formal nomenclature presented in this report for units occurring in KY has been accepted by the Kentucky Stratigraphic Nomenclature Committee. Units that occur largely outside KY are considered informal. Report includes correlation charts, cross sections, and measured sections.

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

Bottom Creek formation (informal) of Breathitt Group of Chesnut (1992); Bottom Creek unit (informal) in Breathitt Formation of Rice and others (1994, GSA Spec. Paper, p. 119-120, citing Chesnut, 1989). Not used. [Rocks assigned to the Bottom Creek formation by Chesnut (1992) = Dark Ridge Member of Lee Formation in Upper Cumberland River district, southeastern Kentucky.]

Source: Publication.

Corr. chart. Bottom Creek Formation (informal) of Breathitt Group. Sandstone, siltstone, shale, and/or mudstone. Recognized in eastern and southeastern Kentucky where it is comprised entirely of the Dark Ridge Member. (In West Virginia, these rocks are incl. in the New River Formation, btw. the Fire Creek coal zone above and Pocahontas No. 8 coal bed below.) Lies below Sewanee Sandstone and above Warren Point Sandstone, both of Breathitt Group. Equivalent to Signal Point Shale in uppermost part of Gizzard Group of Tennessee. Includes Cumberland Gap coal bed in [Upper Cumberland River district], southeastern Kentucky. Age is Early Pennsylvanian (Westphalian; Morrowan).
[Eble and others (2009, Kentucky Geol. Survey, Spec. Pub. no. 10, ser. XII, figs. 5.2, 5.3) placed beds btw. the Fire Creek and Pocahontas No. 8 coals in the TRIQUITRITES SINANI-CIRRATRIRADITES SATURNI (SS) miospore assemblage zone of western Europe (Wesphalian A; Morrowan). Peppers (1996, GSA Memoir 188, pl.) placed these beds in underlying Namurian C, RAISTRICKIA FULVA-RETICULATISPORITES RETICULATUS (FR) miospore assemblage zone of western Europe.]

Source: Publication.