242 Mr. Weaver on Floetz Formations. [Oct. 



Hence I find it necessary to give a fuller exposition of my views 

 on this subject, in which I propose to show that a perfect iden- 

 tity subsists between those formations in the British isles and 

 on the Continent ; and that in fact they all three belong to the 

 first floetz period.* 



I enter upon this task the more willingly, as there are, per- 

 haps, few branches of geological inquiry more instructive than 

 that which relates to the occurrence of the same class or group 

 of formations in different parts of the world ; and in a practical 

 point of view, this investigation is of great importance to the 

 miner. The more attentively we consider this part of our sub- 

 ject, the more readily we shall probably assent to the proposi- 

 tion ; namely, that a certain general order or progression prevails 

 in the structure of the earth, from the oldest to the newest form- 

 ations ; that the detail of this order, however, is not constantly 

 the same, but varies in different countries, and sometimes even 

 in the same tract of country. 



On the Floetz, First Series, as comprehending the Formations of 

 In the British Jsles. In Germany. 



1. Old red sandstone. 1. The rot he todtliegende of 



Lehman, Werner, Karsten, 

 Von Buch, Heim, Freiesleben, 

 &c. 



The old, or first Jloetz sand- 

 stone formation of Werner. 



2. Mountain, or carbonife- 2. The limestone subordi- 

 rowst limestone. nate to the rothe todtliegende 



of ditto. 



3. Coal formation. 3. The coal subordinate to 



the rothe todtliegende, and 



The coal formation reposing 

 upon it. 



Eigentliche Steinkohlen for- 

 mation of ditto. 



In the Netherlands. 



1. Poudingueset gres""| ^ ^ 

 rouges. ^ I c.2 



2. Calcaire interme- }► £ ^ 

 diare. L o 



3. Gres houiller. JO m 



• That is, according to their true position in the geological series, and always consi- 

 dering the old red sandstone as the first member of the floetz class, which rank it has 

 always held, even from the time of Lehman. To denominate that formation a grey- 

 w^cke is to have little respect to mineralogical character, or to general relative position, 

 by both of which it is sufficiently distinguished, although, in point of affinity and age, 

 it stand next to the transition conglomerate, and sandstone. So forced a construction 

 seems to have originated in a loose expression of Werner, respecting the Derbyshire 

 jfraexpne, which was said to be transition at a time when its relations had not been fully 



