Pg. 119, 120, 121. Barnsdall formation of Ochelata group. Consists of sandstone and limestone. At Kansas-Oklahoma line, consists of Birch Creek limestone at base and two unnamed shale members that are separated by inconspicuous unnamed sandy limestone less than 2 feet thick. Southward this unnamed sandy limestone grades into sandstone continuous with Okesa sandstone member. Farther south, the Okesa is much thicker at the expense of the two shale members, and includes, as its basal bed, limy sandstone that is equivalent to Birch Creek limestone. Upper shale member contains Wildhorse dolomite bed only a few feet below the top of formation. Unconformably overlies Wann formation; conformably underlies Tallant formation (new). Thickness about 100 feet. Age is Late Pennsylvanian (Missouri).
Type locality: area between Barnsdall and Wolco, in T. 24 N., R. 11 E., Osage Co., north-central OK. Name is from town of Barnsdall, formerly Bigheart. This is same town from which Bigheart sandstone was named (White and others, 1922). Type locality of Bigheart is in hills west of the town, and name of town has been changed to Barnsdall. Town now called Bigheart is in sec. 3, T. 27 N., R. 10 E., Osage Co., and is on the outcrop of neither Barnsdall formation or Bigheart sandstone.

Source: US geologic names lexicon (USGS Bull. 1200, p. 218-219).