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. Marine sequence overlying the Mason coal bed and its lateral correlatives is here informally named the Partridge shale member of the Grundy formation. Described as calcareous shale with calcareous concretions. [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).

Corr. chart. Partridge shale member (informal) of Grundy Formation of Breathitt Group. Shale and/or mudstone. Recognized in eastern and southeastern Kentucky. Lies in upper part of Grundy Formation, below Betsie Shale Member of Pikeville Formation [which Eble and others (2009, Kentucky Geol. Survey, ser. XII, Spec. Pub. 10, fig. 5.2) placed at the Langsettian/Duckmantian (Westphalian A/B) boundary on basis of miospores], and above Molus shale member (informal) of Grundy Formation. In eastern Kentucky [Big Sandy district] lies between the Manchester (Zachariah, Clintwood, Williamson) and the Millard (Glamorgan) coal beds; is interbedded with upper part of Corbin Sandstone (unranked) in Grundy Formation. In southeastern Kentucky lies between the Hance coal zone and Mason rider coal. Age is Early Pennsylvanian (Westphalian; Morrowan).
[Peppers (1996, GSA Memoir 188, p. 9, pl.) placed rocks = Partridge, btw. the River Gem and Mason coals of eastern Kentucky, in basal part of Westphalian B, MICRORETICULATISPORITES NOBILIS-FLORINITES JUNIOR (NJ) miospore assemblage zone of western Europe. Eble and others (2009, Kentucky Geol. Survey, ser. XII, Spec. Pub. 10, figs. 5.1, 5.2) placed rocks = Partridge in the underlying RADIIZONATES ALIGERENS (RA) miospore assemblage zone of western Europe, uppermost part of Langsettian (uppermost part of Westphalian A).]
[See also Chesnut, 1997 (revised Oct. 12, 1999), Stratigraphy of the coal-bearing strata of the Eastern Kentucky coal field, available online through the Kentucky Geol. Survey (http://www.uky.edu/KGS/coal/coalcorrel.htm).]

Source: Publication.