Featherstonhaugk^s Geological Report. 



21 



perficiai part of the crust of the earth is not incoherent and 

 at random, but has been produced by causes both constant 

 and general ; for since, after a mature examination of the Eu- 

 ropean beds, evidences of the same geological epochs are 

 found at the most distant points, it would be infinitely a more 

 strange thing if affinities were not found here, than it can 

 possibly be in the eyes of sceptical persons to find some of 

 the beds in both hemispheres considered as equivalents. 



Although this order of succession exists, yet in no part of 

 the world have all these beds been found uninterruptedly 

 overlying each other, as they are represented in the geologic 

 cal column. This perpendicular section only represents all the 

 beds which have been described as coming into their places 

 in succession to each other. If, however, all these deposites 

 had been made in the same locality, and had not been subse= 

 quently disturbed, such a section might have existed in nature. 

 But, as has been before observed, some of them are wanting 

 in every country. In the tabular view, at page 24, the strata, 

 for the sake of convenient reference, are grouped. The beds, 

 from the variegated or red marl to the Portland oolite, both 

 inclusive, comprehend what English geologists have named 

 the oolitic series ; this group has an average thickness of 

 2,700 feet in England, but has not yet been found on any part 

 of this continent. Chalk, also, which has an average thick- 

 ness of about 700 feet in Europe, is not found here, although 

 many associate strata belonging to the group it is a member 

 of, and lying both above and below it, are well developed in 

 the United States. This remarkable deposite in the countries 

 where it exists, contains in the upper part of its white mass 

 numerous irregular beds of nodules and plates of the dark- 

 colored flint of commerce. Haldon Hill, in Devonshire, consists 

 of green sands superimposed upon red marl, the intervening 

 beds being wanting. But the chalk which lies upon the 

 green sands in the tabular view^ is not there, and an unobserv- 

 ing traveller would cross this lofty barrier without being re- 



