SANDSTONE, SHALE, AND COAL. Ill 



3. Rough coai'se sandstone, partly calcareous. 



4. Calcareous sandstone, or arenaceous limestone, hardened with 

 iron, and containing shells. 



5. Grey limestone, of a dusky colour. 



6. Blue limestone, forming a bed of considerable thickness. 



7. Thin seams of shale, partly bituminous, alternating with thin 

 beds of sandstone. 



8. A massive bed of sandstone, 8 or 10 feet thick. 



9. A bed of shale. 



10. Schistose sandstone, splitting into thick slates, or flags. 



11. Bituminous shale, of a fine texture, with a mixture of coal. 



12. Whitish sandstone; the lowest bed at the wyke. 



This series is not seen complete in any one spot, for as the 

 higher beds in the list are found only on the south side of the wyke, 

 so the lower beds do not appear till we reach the north side, the rise 

 of the strata being in that direction. 



A bed corresponding with No. 7 is usually found under the blue 

 limestone wherever it occurs. It varies greatly in its composition; 

 sometimes, as hei'e, presenting a mixture of shale and sandstone, in 

 alternate seams; sometimes, as in Scugdale, consisting of sandy shale; 

 and sometimes composed entirely of schistose sandstone, of which 

 we have an instance in the ravines below Sneaton. Under all these 

 variations, the bed retains more or less of its bituminous quality. 



No. 10 affords very good flags, for which purpose it has been 

 sometimes quarried. Some of the other sandstone beds at this wyke, 

 and to the north of it, are also quarried, for architectural uses. 



In No. 11 we have the first decided appearance of coal. A little 

 to the north of the wyke, beyond the place where the higher strata 

 are interrupted, as noticed in p. 103, a seam of coal is found, which 

 has sometimes been wrought. Like the other coal seams along the 

 shore, it is so thin, that, unless where it is of very easy access, it will 



