78 



ILLINOIS STATE GEOLOGICAL SURVEY 



Johnson Counties in southern Illinois. The 

 coals mined near Makanda in southern 

 Jackson County ("Makanda" Coals in this 

 report) and the Reynoldsburg Coal, at the 

 top of the Caseyville Group, may be as 

 much as 28 inches thick, which is regarded 

 as minable in Illinois (Cady, 1952). The 

 Battery Rock Coal has been mined in east- 

 ern Hardin County. 



The Caseyville is considered equivalent 

 to the upper part, at least, of the Morrowan 

 of the Midcontinent region (Wanless, 

 1956) , to the New River Group of the 

 Pottsville Series of the Appalachian region 

 (Wanless, 1955) , and to the Westphalian A 

 (Moore et al., 1944; Kremp, 1955) and Na- 

 murian C of Europe (Moore et al., 1944) . 



In terms of floral zones, as defined by 

 Read (1947) , the Caseyville Group con- 

 tains plants of zone 2 (Zone of Mariopteris 

 pottsvillea and Aneimites) and of zone 3 

 (Zone of M. pygmaea) . Plants of zone 2 are 

 known from the "Wayside Member"; plants 

 of zone 3 are known from the Drury Shale 

 which overlies the Battery Rock Coal. Ko- 

 sanke (1947) noted that the dominant gen- 

 era, defined on the basis of small spores, of 

 the Caseyville Group are Densosporites and 

 Lycospora. He noted (1950) the absence of 

 three genera that are represented in the 

 Tradewater Group: Alatisporites, Cirratri- 

 radites, Reinschospora. 



The plus 65-mesh residues of 20 samples, 

 five of which were from Kentucky and In- 

 diana, were studied. Samples from south- 

 ern Illinois were from Hardin, Jackson, 

 Johnson, Pope, and Wabash Counties. In 

 addition, three samples of coaly streaks or 

 thin coals from sinkhole deposits of early 

 Pennsylvanian age were obtained from 

 Kankakee and Will Counties. One sample 

 of coal from the Mansfield (?) Formation 

 in Indiana also was included. 



Caseyville Coals 



A number of thin coals are known from 

 within 60 feet above the base of the pre- 

 Pennsylvanian unconformity in diamond 

 drill cores in Wabash County, just to the 

 east of the deepest portion of the Illinois 

 Basin. Two coals from each of two cores 

 were examined for plus-residue content. 



The following genera and species were 

 represented in a 934-inch coal (maceration 

 798) , about 13 feet above the unconformity 

 at a depth of 1543 feet 10 inches in Forest 

 Oil Company core, No. M021, NW14 C 

 sec. 3, T. 1 N., R. 12 W., Wabash County: 



Triletes globosus var. (B) (A) 

 Spencerisporites cf. S. radiatus (A) 



T. horridus (A) 



T. mamillarius (C) 



T. triangulatus (C) 



Triletes ? corycilis n. sp. (C) 



Cystosporites giganteus (C) 



T. subpilosus (R) 



Monoletes (R) 



The assemblage in the coarse residue of 

 the French Lick Coal (maceration 151), 

 from the Wortinger Whetstone quarry, 

 Orange County, Indiana, bears a marked 

 resemblance to the one described above. 

 The French Lick Coal apparently lacks 

 spores of T. horridus, T. triangulatus, and 

 Monoletes. However, T. ? corycilis is known 

 only from these two coal beds. Wanless 

 (1955) stated that the Indiana coal yields 

 the oldest flora known in the Eastern In- 

 terior Coal Basin and correlates with the 

 lower Pottsville or Pocahontas Group of 

 West Virginia. 



In the Forest Oil Company core a thin 

 coal, 6 inches thick, occurs at a depth of 

 1520 feet 1 inch, about 23 feet above the 

 sample described above. A third coal (mac- 

 eration 797), 13 inches thick, occurs at a 

 depth of 1506 feet 1 inch, about 37 feet 

 above the lowest coal. 



The following genera and species were 

 recognized from maceration 797: 



Triletes globosus var. (B) (A) 



T. subpilosus (C) 



T. triangulatus (P) 



Spencerisporites cf. 5. radiatus (R) 



Cystosporites giganteus (R) 



Calamospora cf. C. laevigata (R) 



Spores of T. globosus var. (B) make up 

 about 95 percent of large spore content of 

 this residue. 



Two other thin coals occur in another 

 Wabash County core at depths of 1487 feet 

 6 inches and 1478 feet 3 inches, the latter 

 being at least 33 feet above the base of the 

 Pennsylvanian. The lower 534-inch coal 

 (maceration 796) , from Forest Oil Com- 

 pany core, No. K031, SE14 NW14 SE14 sec. 



