304 Geological Society : — Mr. Lyell on the 



If this explanation be allowed, the author observes, it may easily 

 be conceived that when a much greater portion of the globe was 

 covered with water, and the evaporating surface consequently larger, 

 currents of air charged with aqueous vapour prevailed still more, 

 and modified the ancient climate even in still higher latitudes. 



In conclusion, Mr. Everest remarks, that Scandinavia presents 

 another instance of the carrying power of fluids with respect to heat, 

 the coast, and even the bays, being free from ice to the latitude of 

 71°, owing probably to a south-westerly current in the adjacent 

 ocean j and he states, on the authority of persons who have win- 

 tered at Spitzbergen, that south-west winds are usually accompanied 

 by rain and thaw even in December and January. 



A paper was then read, "On the Tertiary Formations and their 

 connection with the Chalk in Virginia and other parts of the United 

 States," by Charles Lyell, Esq., V.P.G.S.* 



Having examined the most important cretaceous deposits in New 

 Jersey, Mr. Lyell proceeded, in the autumn of 1841, to investigate 

 the tertiary strata of Virginia, the Carolinas and Georgia, with a view 

 to satisfy himself, first, how far the leading divisions of the tertiary 

 strata along the Atlantic border of the United States agree in aspect 

 and organic contents with those of Europe ; and, secondly, to ascer- 

 tain whether any rocks containing fossils of a character intermediate 

 between those of the cretaceous and the eocene beds really exist. The 

 conclusions at which he arrived, from his extensive survey, are given 

 briefly as follows : — 1. The only tertiary formations, which the author 

 saw, agree well in their zoological types with the eocene and miocene 

 beds of England and France j 2. he found no secondary fossils in 

 those rocks which have been called upper secondary, and supposed to 

 constitute a link between the cretaceous and tertiary formations. 



1. Virginia. — The tertiary strata bordering the James River, Mr. 

 Lyell says, have been well described by Prof. H. D. Rogers and Dr. 

 Rogersf ; and, he adds, they are also noticed in Mr. Conrad's ex- 

 cellent work on the tertiary strata of the United States. At Rich- 

 mond, Mr. Lyell examined the remarkable bed of infusorial clay 

 described by Prof. Rogers J, consisting of an impalpable siliceous 

 powder derived from cases of microscopic animalcules. It varies in 

 thickness from twelve to twenty-five feet, and is interposed between 

 eocene greensands and miocene clays ; but Mr. Lyell agrees with 

 Prof. Rogers in considering it as probably belonging to the former 

 epoch. 



Similar eocene greensands, very much resembling the cretaceous 

 greensand of New Jersey, occur at Petersburg, thirty miles south of 

 Richmond, and are overlaid by a large deposit of miocene marls 

 abounding in testacea different from those of the subjacent sands. 

 Among the fossils of the latter deposit are a Venericardia scarcely 

 distinguishable from V. planicosta of the London clay, also an Ostrea 



* For abstracts of a series of papers by Mr. Lyell and others on the geo- 

 logy of North America, see present volume, p. 180. 



f American Phil. Trans., New Series, vol. v. p. 319 et seq. 1835, and 

 vol. vi. p. 347 et seq. 1839. } States' Report, 1840. 



