57 



percent) also increased sharply to become 

 second in importance, but Punctatis pontes 

 (7.7 percent) was at its minimum for all the 

 samples macerated from the Fithian Cyclo- 

 them. Calamospora, Triquitrites, Reticulati- 

 sporites, Raistrickia, Cirratriradites, Alatispo- 

 rites, Cadiospora, Gravis pontes, Florinites, 

 and Vesicaspora were numerically minor con- 

 stituents of the small spore assemblage. 



Crassispora (32 percent) and Punctatispo- 

 rites (31 percent) were of almost equal 

 abundance in the black shale (maceration 

 1170-E) underlying the limestone. Florinites 

 increased significantly to 17.7 percent and 

 was at its observed maximum for the cyclo- 

 them, as was Pityosporites (4.7 percent) . 

 Endosporites decreased to 7.3 percent, and 

 Gravisporites increased to 3.3 percent. Granu- 

 latisporites, Calamospora, Triquitrites, Cirra- 

 triradites, and Alatisporites were rare. 



In the gray shale (maceration 1170-G) 

 above the limestone, Punctatis pontes (62 per- 

 cent) again became by far the dominant 

 genus, followed by Florinites, which consti- 

 tuted 12.3 percent of the total. Calamospora 

 (5.7 percent), Granulatis pontes (4.0 per- 

 cent), Laevigatos pontes (3.3 percent), and 

 Vesicaspora (2.7 percent) were fairly com- 

 mon. Crassispora decreased markedly to only 

 2.3 percent. Other genera included Triqui- 

 trites (2.3 percent), Endosporites (1.7 per- 

 cent) , and Columinis pontes ( 1 percent) . 

 Raistrickia, Cirratriradites, Latipulvinites, 

 Gravisporites, Indospora, Limitis pontes, Pi- 

 tyosporites, Rhizomaspora, and Lycospora 

 were each less than 1 percent of the spore 

 assemblage. 



SPORES OF THE 



HENSHAW FORMATION, 



UNION COUNTY, KENTUCKY 



The uppermost 250 feet of a diamond drill 

 core of the Henshaw Formation of western 

 Kentucky, sampled (maceration 1122) for 

 the present study, is described at the end of 

 the report. The top of the core is approxi- 

 mately 1200 feet above the Carthage Lime- 

 stone Member (equivalent to the Shoal Creek 

 Limestone Member of Illinois) . 



Of 26 samples of various lithologies (text 

 fig. 16) macerated from the section, only 11 

 yielded spores. Preservation of the spores in 



many of these samples was very poor. As a 

 large number of samples failed to yield spores 

 (macerations 1122-B through 1122-D, 1122- 

 H, 1122-1, 1122-K through 1122-N, 1122-R, 

 and 1122-U through 1122-Y), several wide 

 gaps exist in the data concerning the plant 

 microfossil succession. In maceration 1122-A, 

 a dark shale, and maceration 1122-Q, a 

 sandstone directly overlying the middle coal 

 of the part of the Henshaw Formation stud- 

 ied, a great variety of well preserved spores 

 was obtained. 



Punctatis pontes (61.3 percent) was by far 

 the dominant genus in the dark gray shale 

 (maceration 1122-A), the lowest sample mac- 

 erated. Granulatis pontes and Endosporites 

 were second and third in relative abundance, 

 with 10.7 percent and 5.3 percent, respec- 

 tively. Calamospora (5 percent), Laevigato- 

 sporites (4.0 percent), Florinites (3.0 per- 

 cent), and Crassispora (2.3 percent) were 

 frequently encountered. Lycospora and Den- 

 sosporites totaled less than 1 percent, and the 

 significance of their presence is discussed 

 later. The rest of the small spore assemblage 

 included minor percentages of Triquitrites, 

 Raistrickia, Ahrensisporites, Cirratriradites, 

 Reticulars pontes, Micr or eticulatis pontes, Re- 

 inschospora, Convolutispora, Striatosporites, 

 Lundbladispora, Latipulvinites, Secarispo- 

 rites, Gravisporites, Indospora, Trivolites, 

 Dictyotriletes?, Wilsonites, Strotersporites, 

 Potonieis pontes, and Pityosporites. 



The most obvious feature in the spore dis- 

 tribution of the lower coal (maceration 1122- 

 E) was the great increase in the percentage 

 of Endosporites (57.6 percent) compared to 

 the occurrence of this genus in the associated 

 underclay. Punctatis pontes (29.2 percent) 

 was next in abundance, followed by Cala- 

 mospora (8.0 percent), Granulatis pontes (2.8 

 percent), and Florinites (1.2 percent). Tri- 

 quitrites, Raistrickia, Laevigatos pontes, and 

 Convolutispora were each less than 1 percent 

 of the small spore assemblage. 



Punctatis pontes (73.7 percent) again be- 

 came the dominant genus in the coaly shale 

 (maceration 1122-F) immediately above the 

 coal, where it reached its maximum observed 

 peak. Endosporites decreased sharply to 19.3 

 percent. Calamospora declined to 2.7 per- 

 cent, and Granulatis pontes remained at about 

 the same relative abundance. Triquitrites and 



