cell 



cell cap 



cell 



thimble 



thimble of 

 parent cell 



cellulose wall 



B 



Figure 1 A. Cross section of a pair of modern cells of Bolryococcus braunii Kiitzing. B. Colony of B. 

 braunii. Cells, cell caps, and cell walls are not present in fossil Botryococcus (adapted from Blackburn 

 and Temperley 1936). 



Paleozoic algae preserved in torbanite without appre- 

 ciable modification." White's description (in Bain 1906) 

 of algae in the Galena Formation of Illinois strongly 



suggests that Botryococcus can be traced back at least to 

 the Ordovician. 



COAL BEDS THAT CONTAIN BOTRYOCOCCUS 



Coals containing Botryococcus are widely distributed in 

 the Illinois Basin (table 1 and fig. 2). Analyses of the 

 samples are discussed below according to stratigraphic 

 unit, oldest to youngest (fig. 3). References in the text 

 are to the unit name in southern Illinois. Correlation 

 with equivalent (but occasionally differently named) 

 units elsewhere in the basin are given in figure 3. 



Reynoldsburg Coal Bed (Illinois) 



Kosanke (1950) studied the palynology of the Rey- 

 noldsburg Coal Bed near the town of Reynoldsburg, 

 Johnson County; and Smith (1957) reported on strippa- 

 ble reserves of the coal in southern Illinois. Trask and 

 Jacobson (1990) mapped the coal outcrop near 

 Reynoldsburg. The coal lies just above the Pounds 

 Sandstone Member and at the base of the Tradewater 

 Formation (formerly Abbott Formation; Greb et al. 

 1992). It is late Morrowan in age (fig. 3). In places the 

 canneloid and bituminous coal grades upward into an 

 oil shale several feet thick, called the Ozark oil shale, 

 that was locally used in cookstoves and fireplaces. At 

 site 28 (table 1), the Reynoldsburg contains abundant 

 Botryococcus and opaque, finely divided kerogen. 

 Spores in maceration 2695 are poorly preserved, but the 

 assemblage is dominated by Densosporites, which were 

 produced by small lycopods. 



Botryococcus is rare in the coaly shale at site 29, 

 about 2 miles east of Reynoldsburg, and in the coal at 

 site 31, about 11 miles east of Reynoldsburg. The can- 

 neloid coal and bituminous shale at site 29 were used 

 by Barrett (1922) for experimental distillation of the 

 deposits as a possible source of oil. About 6,000 cubic 



feet of gas and 36.6 to 45.1 gallons of crude tar per ton 

 of coal shale were distilled. At sample site 31, Laevi- 

 gatosporites (38%) and Densosporites (25%) dominate, 

 and only 24% of the spore assemblage is made up of 



Lycospora. 



Breckinridge and Bell Coal Beds (Kentucky), 

 Bell Coal Bed (Illinois), and St. Meinrad Coal 

 Member (Indiana) 



Hower et al. (1986) described the petrology and geo- 

 chemistry of the Breckinridge coal bed in Hancock 

 County, Kentucky. Botryococcus braunii is very abun- 

 dant in the seam, which they considered a torbanite. 

 Botryococcus is also abundant in a sample of the Breck- 

 inridge coal examined from site 42 in Breckinridge 

 County, 8 km south of Cloverport. Hower et al. (1986) 

 stated that the seam is Morrowan (Westphalian A) in 

 age. The spores are not sufficiently well preserved to 

 permit a percentage count; the presence of Renisporites 

 confossus and Endosporites globiformis and the lack of 

 Schulzospora rara, however, indicate that the coal is early 

 Atokan (early Westphalian B) in age and probably cor- 

 relates with the Bell coal bed (fig. 3). 



At sites 26 and 27 in Johnson County, Illinois, the 

 Bell Coal Bed, which is stratigraphically about 12.2 m 

 above the Reynoldsburg Coal, contains rare specimens 

 of Botryococcus. Maceration 2611 is from coal fragments 

 collected around an old mine entrance, and maceration 

 3059 is from an abandoned strip mine. A total of 95% 

 and 74% of the spore assemblages in macerations 2611 

 and 3059, respectively, are Lycospora. Cristatisporites in- 

 dignabundus and Densosporites annulatus, which were 



