Pg. 33, 43, and pl. XLA. Hignite formation of Pottsville group. Shales, sandstones, and coals, 460 feet thick, lying between top of Red Spring coal above and base of Hignite coal below in Cumberland Gap coal field. Underlies Bryson formation and overlies Catron formation. Age is Pennsylvanian.
[Named from Hignite Creek, near Middlesboro, Bell Co., southeastern KY. Extends into northeastern TN.]
[GNC remark (ca. 1936, US geologic names lexicon, USGS Bull. 896, p. 957): Later studies by D. White show Hignite formation is of late Pottsville age is represented in time interval of Kanawha formation.]

Source: US geologic names lexicons (USGS Bull. 896, p. 957; USGS Bull. 1200, p. 1761).

Pg. 7, passim. Hignite formation of Pottsville group. Underlies Bryson formation; overlies Catron formation. Includes Reynolds sandstone member. [Age is Middle Pennsylvanian.]

Source: US geologic names lexicon (USGS Bull. 1200, p. 1761).

The USGS currently classifies the Hignite as a formation in Breathitt Group on the basis of a study now in progress. [See K.J. Englund and others, 1961, USGS Geol. Quad. Map GQ-172, 1 sheet, scale 1:24,000 (http://ngmdb.usgs.gov/Prodesc/proddesc_620.htm); K.J. Englund and others, 1963, USGS Bull. 1142-B (http://ngmdb.usgs.gov/Prodesc/proddesc_20876.htm).] Term Pottsville Group not used in Kentucky. Age is Middle Pennsylvanian.

Source: US geologic names lexicon (USGS Bull. 1200, p. 1761).

[See p. A39, A43 (fig. 9). †Hignite Formation of Breathitt Group. In upper part of Breathitt Group, between the †Bryson (above) and †Catron Formations, along Pine Mountain Fault, in southeasternmost Kentucky, and bordering area of Tennessee and Virginia. Is not formally abandoned herein but its use is clearly discontinued; it is not distinguishable on basis of lithic character and cannot be traced laterally with consistency. As originally defined in the Log Mountains, it extended from base of Hignite coal to top of Red Spring coal. Following the general practice of placing unit boundaries at the base rather than at the top of coal beds, geologists later excluded the Red Spring, placing it in the overlying Bryson. Beyond its type area the upper contact of the Hignite has not been mapped. Rocks of the †Hignite are transferred to the Breathitt Formation (reduced in rank to conform with USGS usage elsewhere).
The Hignite was formally abandoned by Rice and others in their glossary (1994, GSA Spec. Paper 294, p. 129, citing McDowell and others, 1985).]

Source: Publication.