160 



THE CARBONIFEROUS SYSTEM. 



Coal-group 14. 



An erect ribbed Sigillaria appears in the roof-shale. The 

 coal contains many flattened Sigillarice^ also Triffonocarpa, 

 Cordaites, and vascular bundles of ferns. 



ft. in. 

 (Arenaceous understone with ironstone nodules and 

 Stigmaria, and carbonaceous shale) . . .79 

 ( Carbonaceous shale. 



Coal-group 12 •< Coal, 2 inches 2 



( Argillaceous underclay, ironstone, and Stigmaria. 



This coal is hard and laminated, with many vascular bundles 



of ferns upon its surfaces. 



(Gray sandstone and gray argillaceous shale) . .12 

 ( Gray argillaceous shale. 



Coal-group 13 ■< Coal, 7 inches 7 



( Gray argillaceous underclay, ironstone, and Stigmaria. 



The roof contains erect stumps, not distinctly marked. 

 The coal has indications of bark of Sigillaria, and is hard and 

 shining, with a coarse earthy layer in the middle. 



(Gray shale) 7 



Gray shale, as above. 



Coal, 4 inches. 



Gray argillo- arenaceous underclay, ironstone, and 



Stigmaria, 1 foot 6 inches. 

 Coal, 2 inches . . . . . . .20 



Gray argillaceous underclay, ironstone, acndi Stigmaria. 



The upper coal has impressions of bark of trees and Cor- 

 daites, especially in its upper part. 



(Gray and reddish shale and gray sandstone, with 



Stigmarian soils at two levels) . , . . 52 

 ' Gray shale. 

 Carbonaceous shale, 2 inches. 



Coal-group 15 <i Argillaceous underclay, ironstone, and (Sii^maria, 1 ft. 



Coal, 1 inch 13 



Argillaceous underclay, ironstone, and Stigmaria. 



The upper shaly bed is a coal interlaminated with shale, 



which enables the nature of the coaly matter to be ascertained. 



It contains flattened Sigillarice of several species, Calamites, 



Cordaites, Cyperites, leaves of Sigillaria, and Lepidopkylla. 



The clay parting is the roof of the lower coal, and contains 



Cyperites and Cordaites. It has been converted into an 



underclay by the growth of Sigillaria upon it in the formation 



of the upper bed of coaly shale. The lower coal is compact, 



but showed an impression of a Calamite. 



(Gray sandstone and gray and reddish shale, iron- 

 stone nodules) . . . . . . . 16 



Gray argillaceous shale. 



Coal and carbonaceous shale, 2 inches . , .02 

 Keddish argillaceous underclay, ironstone, and Stig- 

 maria. 



Coal- group 16. 



