520 THE WONDERS OF GEOLOGY. Lect. V. 



being largely charged with vegetable remains. They be- 

 long to a period long antecedent to the deposition of the 

 Wealden. 



24. Carboniferous Oolite of Eastern Virginia. — 

 One of the most remarkable features in the geology of the 

 United States of North America, as contrasted with that 

 of Europe, consists in the entire absence of deposits that 

 can be regarded as the equivalents of any of the members 

 of the Oolitic system. With but one exception, no natural 

 records remain of the vast interval of time that must have 

 elapsed, between the close of the Triassic and the com- 

 mencement of the Cretaceous epoch. Some time since, 

 it was suggested by Professor W. B. Rogers, that an 

 extensive coal-field in Eastern Virginia * belonged to the 

 oolitic period ; and this opinion has been confirmed by the 

 recent investigations of Mr. Lyell. This coal-field is about 

 twenty miles from north to south, and from four to twelve 

 miles in breadth from east to west. It is situated in a 

 granitic region, and the lowermost bed of coal rests upon 

 granite. Quartzose grits, sandstones, and shales, are inter- 

 calated with the coal, as in the carboniferous system of 

 Europe. Beds of rich bituminous coal, one being in some 

 places from thirty to forty feet thick, occur in the lower 

 division. 



The fossil plants resemble those of the Oolite of York- 

 shire, (Pecopteris Whitbiensis, Equisetum columnar e, some 

 species of Zamites, Tceniopteris, Neuropteris, &c.) differing 

 specifically, and most of them generically, from those of the 

 older coal formations. From the upright position of many 

 of the Equiseta, Mr. Lyell infers that the vegetables which 

 produced the coal grew on the spot where they are now 



* There are two coal-fields in the State of Virginia; the remarks in 

 the text exclusively refer to that near 'Richmond, the coal measures 

 in Western Virginia belong to the ancient carboniferous system. 



