220 



and having the entire circumference of these fragments drilled all 

 over by some small lithodomous shells ; these fragments attest the 

 consolidation of the lower strata before the deposition of the 

 central beds, and mark an interval in the formation sufficient for 

 the fragments to have been rounded and perforated. 



12. The lowest strata, within the district described, are the upper 

 marl beds of the lias formation on the east of Charmouth ; these 

 are loaded with belemnites, and may represent the Calcaire h 

 Belemnite of the French geologists ; as the lower stony beds of 

 lias at Lyme are equivalent to their Calcaire a Gryphite. On the 

 shore east of Charmouth the marl beds present an almost continu- 

 ous pavement of belemnites, and also contain saurians. 



13. The elevation which has raised all the component formations 

 of the Valley of Weymouth towards an anticlinal axis, has been ac- 

 companied by extensive faults, the most remarkable of which are 

 parallel to the anticlinal axis, and appear to have been contempo- 

 raneous with the general elevation of the district. One of these 

 faults is continuous nearly 15 miles along the escarpment of the 

 chalk of the ridgeway, on the north of Weymouth, and at various 

 places brings up strata of oolite, Portland stone, and Purbeck 

 stone into contact with chalk and greensand ; many sections are 

 given illustrating the effects of these faults, not one of which ap- 

 pears to be anterior to the deposition of the most recent strata in 

 the district. 



14. Subsequently to, or perhaps contemporaneously with the 

 elevation of the strata and production of the faults, the surface has 

 been ravaged by a tremendous inundation which has swept away 

 all the ruins and rubbish of the elevated masses, and has exca- 

 vated valleys of many hundred feet in depth on the surface of 

 the strata that remain. Outlying summits, composed of residuary 

 portions of strata which are continuous along the escarpments on 

 the north and east of the Vale of Bredy, indicate the original con- 

 tinuity of these strata over large portions of that district, from 

 which they have been removed. 



15. Small deposits of diluvium are scattered over many of the 

 hills as well as the valleys, but there are no very thick and con- 

 nected accumulations of gravel ; the force of the water that could 

 produce such enormous excavations must have been far too great 

 to allow the excavated materials to subside so near the rocks from 

 which they were torn, and must have drifted them far away into 

 the continuation of these valleys, in the bottom of the English 

 Channel. 



The authors conclude that they have sufficient evidence to es- 

 tablish the following succession of changes, in the state of that 

 small portion of England which occupies the coast of Dorsetshire 

 and Hants. 



1st. There is a continuous succession of marine deposits from the 

 lias upwards through the oolites, terminating in the deposition of 

 the Portland stone :— during the period of all these formations the 

 district must have been the bottom of an ancient sea. 



