FIELD GEOLOGY. 211 



The dip of the coal-seam, where first crossed has not 

 been ascertained, but beyond the fault its dip is greater 

 by 2 than that of the sand ; on this side they must 

 have the same difference in inclination, the seam 

 therefore dips at 10 30' its apparent angle will be 

 7 30' where crossed by the section. The extremity of 

 the sand where the line again crosses it is dipping 6, 

 apparent dip 4, and the coal-seam 8, which will be 

 shown 5 30' only, on account of the deviation. 



Vertical Section. The beds shown in the section, 

 fig. 22, could not have been continued to so great a 

 depth from their outcrop (nor could the lower ones 

 have been inserted at all) on the evidence obtained 

 only on the surface, although even that would have 

 furnished an approximation to the depth of the Coal- 

 measures beneath the Bunter Sandstone ; the additional 

 particulars were obtained from the proprietor of the 

 coal-mine, and are as given below. 



; . Coal Mine, North Shaft. 



To 100 feet. Soft sandy stone, red and yellow. Level. 

 460 Hard rock. 

 740 Freestone. 



Shales. 



At 800 " Three-foot " Coal, rising N., 3' 3" thick. 

 Shales and Ironstone layer in the middle.. 

 920 Bed of hard blue stone, 8' thick. 



Shales. 

 1080 " Thin Coal," rising North, 1' 6" thick. 



Shales. 



1400 " Lower three-foot " Coal, 3' thick. 

 Shales. 



142 



