264 



Messrs. Bucrland's and Conybeare's Observations on the 



shale would be found a little to the south-east of that point in the direction of 

 the dip. We have also assigned the grounds for believing that an unexplored 

 coal-basin exists along the course of the Severn between Aust and Portishead- 

 point. A trial by boring in the marshes about a mile to the west of King's 

 Weston Down would ascertain whether coal really extends through this basin. 

 No coal has hitherto been found to the south of the Mendip range ; but since 

 the mountain limestone dips beneath the marshes in that direction, and re- 

 emerges in Cannington Park on the north of the Quantoc range, it seems pro- 

 bable that there exists an intermediate basin beneath the red marl, which forms 

 the uppermost substratum in this alluvial tract. 



SECTIONS OF COAL-MEASURES. 



Section 1. 



In lower coal-shale, at Pucklechurch, on the eastern side of the northern 



coal-tract. 



Dip N.N.W. 1 in 3. 



4. 



Descending order. 







Path. Ft. In 



Lias . . . . . ? 



Red marl 







J 



Duns and stone 







? 



Hard seam* 







2 



Duns and stone 







. 35 



Top seam 







2 



Duns and stone 







6 



Hollybush seam 







3 



Duns and stone 







6 



Great seam 







3 6 



* Vein is the technical term used by the miners throughout the Bristol Coal.basin to designate a 

 bed of coal ; but since this term is already appropriated in Geology to the fissures filled with solid 

 stony matter, that intersect the strata, we have substituted for it the word seam. Course is (he 

 term used in the southern coal-tract, when the beds are nearly vertical. Delf is the term in the 

 Forest of Dean. In this and the following sections the names of the seams are printed in italics. 



