130 Geological Remarks on the 



have "Separated the IXth and Xth soils or formations 

 by a double line, to mark the distinction between them 

 and the remaining eight soils ; which our authors seem to 

 consider as composed of rci^ular or undisturbed strata, that 

 is, such as exhibitno marks of violent attrition or mecha- 

 nical mixture, a:-: the alluvial soils almost invariably do; 

 and they, besides, never underlay regular strata. 



r shall now, [ hope, be excused in offering freely, a few 

 of the observations which have occurred to me, in thus 

 analysing the hasty but valuable Memoir of our able and 

 industrious neighbours on the continent ; and comparing 

 it with what 1 know of the ten'cstrial stratification, and 

 which is indeed limited in a great measure to the British 

 Islands. 



England presents us with the opportunity of ex- 

 amining the out-crop, or appearance on the surface, of a 

 vast succession of strata, among which the fourth, or 

 lowest Derbyshire limestone, is,perhaps three miles of per- 

 pendicular depth, below the part of the chalk strata, which 

 are described as the lowest that have been seen or reached 

 in the basin of Paris : for it was ascertained by Mr. IVil- 

 liam Smith several years ago, that 200 feet or more of the 

 lower part of the chalk strata are entirely without layers or 

 nodules of flint ; and that some of these beds contain large 

 cornu-ammonis, nautili, and numerous other shells : this 

 he has proved by an actual examination of very near 700 

 miles in length, of the basset or out-burst of these lower 

 and hard beds of chalk, without flints, reckoning from the 

 Isle of Wight to the westernmost points of the chalk in 

 Dorsetshire and Somersetshire, and thence for the 

 north-east angle of Norfolk ; through Lincolnshire, 

 and Yorkshire to Flamborough-Hcad ; and including the 

 edges of our great southern denudation ''• from Bcachy- 

 IJead in Sussex, to near Petcrsfleld and Alton in f Jamp- 

 shire, and Farnham in Surry; and thence again to Hythe 

 in Kent. And here it may not be amiss to observe, that 

 before I knew Mr. Smith, he had ascertained the peculiar 

 fossils that belong to several of the thin strata, underlaying 

 the whole extent of tb.e edges of this vast mass of chalk, 

 in the same rp.aimcr as the Paris strata overlay it, had col- 

 lected a series of specimens of each fossil, marked and 

 brought together from ns many places; and was well en- 

 titled, and did in fact often exclaim, though perhaps, ia, 



• This denudatipn is shortly mentioned iu the CycjJop.tdia, article Coal, 

 and is further exemplified bv ?. manuscl"i',.it section of the atrata between 

 London and Brightan, made by me in IbOo, which is in the hands of many. 



Other 



