536 



DOKSETSHIRE— DEVONSHIRE. 



[Cir. XX 



remarkable shoal in the channel at the depth of 7 fathoms, 

 called ' the Shambles/ consisting entirely of rolled and 

 broken shells of Purpura lapillus, Mytilus edulis, and other 

 species now living. This mass of light materials is always 

 in motion, varying in height from day to day, and yet the 

 shoal remains constant. 



Dorsetshire — Devonshire. — At Lyme Regis, in Dorsetshire, 

 the ' Church Cliffs,' as they are called, consisting of lias 

 about one hundred feet in height, gradually fell away at the 

 rate of one yard a year, from 1800 to 1829."* 



An extraordinary landslip occurred on the 24th of De- 







• 



$ 



ilB 1 



Fig. 49 



Landslip, near Axmoutk, Dec. 1839. (Rev. W. D. Conybeare.) 



A. Tract of Downs still remaining at their original level. 



B. New ravine. 



C, D. Sunk and fractured strip united to A, before the convulsion. 



D, E. Bendon undercliff as before, but more fissured, and thrust forward 



about fifty feet toward the sea. 

 F. Pyramidal crag, sunk from seventy to twenty feet in height. 

 Cr. New reef upheaved from the sea. 



cember, 1839, on the coast between Lyme Regis and Ax- 

 mouth, which has been described by the Rev. W. D. Cony- 

 beare, to whose kindness I am indebted for the accompany- 

 ing section, fig. 49. The tract of downs ranging there along 

 the coast is capped by chalk (h), which rests on sandstone, 



* 



alternating with chert (i), beneath which is more than 100 

 feet of loose sand (&), with concretions at the bottom, and 

 belonging, like i, to the green-sand formation ; the whole of 

 the above masses, h, i, k, reposing on retentive beds of clay 



* According to the measurement of Carpent of Lyme. 



I 



U) 



