76 



PENNSYLVANIAN SPORES OF ILLINOIS 



Table 2. — -Distribution and Abundance of Genera in No. 6 Coal Bed 

 In percentage of total specimens counted 





I 



II 



III 



Genera 



ABC 



ABC 



A B C 



Punctati-Sporites . . . 

 Granulati-Sporites . . 

 Laevigato-Sporites . 



Cirratriradites 



Endosporites 



Triquitrites 



Calamospora 



Lycospora 



Raistrickia 



Florinites 



Wilsonia 



9-10 8-9 30-35 



40-45 40-45 15-20 

 1-2 Yr-\ 2-3 



¥i-\ 



3-4 3^-1 2-3 



3-4 2-3 6-7 



35-40 40-45 15-20 



1-2 5-6 



y 2 -\ y 2 -\ 10-15 

 y 2 -\ 

 34-1 



8-9 15-20 40-45 



34-1 3^-1 



30-35 30-35 15-20 



1-2 y 2 -\ 3-4 

 y>-\ 



1-2 1-2 3-4 



4-5 5-6 9-10 

 45-50 40-45 15-20 



4-5 3-4 }/ 2 -\ 



J4-i Yt-\ H-i 



5-6 10-15 20-25 



2-3 y-\ 



45-50 40-45 25-30 



2-3 y 2 -\ y-i 



2-3 1-2 5-6 



5-6 y 2 -i y 2 -\ 



2-3 4-5 9-10 

 25-30 30-35 25-30 



4-5 2-3 

 3^-1 3-4 



34-i y 2 -\ y 2 -\ 



y 2 -\ 



34-1 y 2 -\ 



"Spherites" 



Gen. Nov 



I. COAL BELOW THE BLUE BAND 

 II. COAL BETWEEN BLUE BAND AND UPPER SHALE 

 PARTING 

 III. COAL ABOVE UPPER SHALE PARTING TO TOP OF 

 BED 



A. GRAPE CREEK NO. 6 COAL BED (eastern 

 Illinois) 



B. HERRIN NO. 6 COAL BED (southern Illinois) 



C. HERRIN NO. 6 COAL BED (western Illinois) 



spora-granulata sp. nov. comprises 69 per- 

 cent of the genus, but only 14 percent of 

 the total spore content. Punctati-sporites 

 obliquus sp. nov. is the dominant species of 

 the genus in all three counties mentioned in 

 this discussion; however, it is less than three 

 percent of the total spore content in Ver- 

 milion County, not more than five percent 

 in Franklin County, whereas it is the domi- 

 nant species in Fulton County where it is 

 29 percent of the spore content. 



It appears from the foregoing that in the 

 three areas under consideration there were 

 differences in the relative abundance of 

 various plants. Further studies in these 

 three areas should help to establish the 

 validity of the differences indicated by the 

 studies. 



The No. 6 coal bed ranks first in com- 

 mercial importance in Illinois because of its 

 thickness, quality, wide geographic distri- 

 bution and favorable mining conditions. 

 It is the uppermost member of the Carbon- 

 dale group and is an excellent key bed in 

 many counties of the State, partly because 

 of its benched character and association with 

 the Herrin limestone. A persistent part- 

 ing, the blue band, is usually found in the 

 lower portion of the bed although occa- 

 sionally it is found as high as the middle of 

 the bed. In addition to the blue band, one 



to three shale partings less widely distrib- 

 uted are known to be present. 



The usual sequence of strata above the 

 coal is gray shale, black shale, and lime- 

 stone but the coal bed may be overlain by 

 any one of these, and in some localities be- 

 cause of Pennsylvanian erosion and sub- 

 sequent deposition, sandstone or siltstone' 

 rests directly upon the coal bed with the 

 normal caprock, gray and black shale, being 

 "cut out." 



The strata below the coal bed usually 

 contains a well developed underclay al- 

 though this is locally replaced by shale, 

 sandstone, or siltstone. In many places to- 

 ward the base of the underclay limestone 

 nodules appear locally representing a transi- 

 tion zone which may develop into an under- 

 clay limestone. The underclay limestone 

 is usually non-fossiliferous, but the core of 

 a drill-hole located near the center of the 

 SE. \/ 2 sec. 4, T. 4 S., R. 1 E., Jefferson 

 County, contained marine fossils at the base 

 of limestone. In southern Illinois the un- 

 derclay limestone may locally be absent. 



It is apparent from the discussion pre- 

 ceding (see also fig. 6) that the strata ad- 

 jacent to the No. 6 coal bed are somewhat 

 variable. Variations of the sort mentioned 

 may in some instances result in uncertainty 

 in the identification of a coal bed when made 



