220 



THE WONDERS OF GEOLOGY. 



Lect. III. 



the leading lithological features of this system of deposits, 

 which we will now examine more in detail. 



The distribution of the tertiary strata over Europe, 

 appears to be in areas more or less well defined. In our 

 own Island, there are the basins of London and Hampshire, 

 which probably were originally united ; and the remains of 

 other series of beds in Yorkshire, Norfolk, Suffolk, Essex, 

 &c. The metropolis of France is situated within the con- 

 fines of a tertiary area ; and in the southern and northern 

 provinces of that country, there are extensive tracts of 

 similar deposits. In Auvergne, they are associated with lavas 

 and scoriae of ancient volcanic eruptions, and constitute a 

 district of unrivalled geological interest. In the Sub- Apen- 

 nines, they are largely developed ; and in other parts of 

 Sicily and Italy they insensibly pass into vast beds of 

 modern origin, which are still in progress of formation. 



In the United States, tertiary marls, clays, and sands, are 

 spread over considerable areas, between the Alleghany 

 mountains and the Atlantic, resting upon sands and marls 

 belonging to the chalk formation. In Maryland and 

 Virginia, there are extensive deposits of this class, remark- 

 able for their organic composition, as we shall hereafter 

 have occasion to notice. 



15. Subdivisions of the Tertiary System. — The 

 divisions of the Tertiary system, adopted by geologists, 

 are concisely expressed in the following synopsis.* 



i Freshwater and marine \ 

 strata, containing but a 

 very few extinct species 

 of shells. Abundance 

 of existing species, in- 

 dicating a marine fauna 

 not essentially different 

 from that which now 

 prevails in the present 



/ 



I. Pliocene; 



or 



Upper Tertiary. 



\ 



Fluvio-marine beds 

 on the eastern 

 coast of England. 

 TheNorwichCrag. 

 Sub-Apennine de- 

 posits ; and those 

 of Palermo, and 

 other parts of Si- 

 cily. 



See Mr. Lycll's Elements of Geology, vol. i. p. 2S4. 



