100 Mr. Tate on the Geology and Archceology of Beadiiell. 



organisms, its mineral composition and picturesque appear- 

 ance. It is 30 feet in thickness, and being very hard, resists 

 more effectively, than the other rocks, the destructive action 

 of the sea. Resting, however, on a soft shale which is easily 

 broken up and washed away by the tides, this superincumbent 

 limestone is deprived of support, and time after time, large 

 masses tumble down from the cliff into the sea. It now 

 forms a narrow point running into the sea about one quarter 

 of a mile ; but the tides and high seas are still working 

 away the lower and softer beds, which connect this pro- 

 montory with the land, and in the course of a few centuries 

 it will become an island on the flow of every tide. This 

 limestone is of a buff colour and generally of a crystalline 

 structure. It is a magnesian limestone, being composed of 

 carbonate of magnesia and carbonate of lime. Besides con- 

 taining Productus giganteus and other commoner mountain 

 limestone fossils, there abound in it large masses of the 

 corals Lithostrotion hasaltiforme and ChoBtetes septosus ; 

 and occasionally we find Syringopora ramulosu, which is a 

 rare coral in the Northumberland beds. These distinctive 

 organisms are excellent guides in tracing the range of this 

 sill ; northward I have found it at Holy Island, and south- 

 ward I have traced it to Spittleford, near to Embleton, and 

 thence to Dunstan, Craster, and Shilbottle ; and thence in a 

 south-west direction to Whittle, Newton-on-the-Moor, Fram- 

 lington, and across the Coquet to Ward's Hill and Rothley. 

 It should be noticed, that the magnesian character of this 

 limestone is a local phenomenon, and seems in some way to 

 arise from its neighbourhood to basalt. In several parts of 

 its range, as at Shilbottle and Framlington, it is a compara- 

 tively pure carbonate of lime. 



There are eighteen different coal seams in the section ; most 

 of them are thin and of an inferior quality, none, excepting 

 two, exceeding 2 feet in thickness, and their aggregate 

 thickness is only 24 feet 4 inches. I'hat which is called the 

 Beadnell coal (number 35 of the section) has been worked 

 both for domestic use and for burning lime. It is of variable 

 thickness, seldom less than 2 feet 6 inches, and generally 

 about 3 feet ; but on Mrs. Taylor's estate, it has been found 

 as much as 6 feet thick, and of a better quality than in other 

 localities. It lies there, however, below the sea level ; and as 

 the sea sometime ago broke into a neighbouring colliery, due 

 precautions would be necessary, to prevent a similar irrup- 

 tion, in the event of this more valuable portion of the coal 

 seam being worked for the use of the district. 



