Messrs. Bucrland's and Conybeare's Observations, &c. 211 



0)1 the two Series of Rock Formations. 



Two great series of rocks occupy our district, the distinction between which 

 is strongly marked, every circumstance seeming to indicate the lapse of a con- 

 siderable interval of time between the deposition of the last beds of the former 

 series and the first beds of the latter. 



The first and lowest of the two series is composed of those rock-formations, 

 which, commencing with the grey-wacke slate and other transition-rocks of 

 the Wernerians, terminate upwards with the independent coal-formation of 

 the same school. The highest of the transition-rocks graduate so insensibly 

 into the lowest of those which succeed to them *, that it is difficult to assign 

 the precise limits at which the former are to be considered as ending, and the 

 latter as beginning. The distinction between the remoter parts, however, is 

 sufficiently obvious. 



The rock-formations of the first series, beginning with the lowest, are the 

 following : — 



1. Grey-wacke. 



2. Transition limestone. 



3. Old red sandstone. 



4. Carboniferous or Mountain-limestone. 



5. Coal-measures. 



The second and uppermost of the two great series of rocks comprehends 

 some of the lowest formations, termed j^oe^a by the Wernerians. This series 

 reposes on the first. The members of this series, which we here have occa- 

 sion to treat of, beginning with the lowest, are the following : — 



1. Newer red sandstone : comprehending 



a Dolomitic conglomerate f, 

 b Red sandstone, 

 c Red marl. 



2. Lias. 



• 3. Oolite. 



* One of the authors has elsewhere expressed his opinion on the misapplication of the epithet 

 *' floetz " to the three last rocks of the first series. See Outlines of Eng. Geol, book 3. chap. 1. 

 Were the tertD first Jloetz applied to the carboniferous limestone, it must produce confusion 

 between English and Continental geologists ; for the latter uniformly apply that term to the 

 limestone associated with the bituminous marl.slate of the Hartz, Mansfield, &c., which is now 

 universally admitted to be contemporaneous with our newer dolomite. On the old and newer red 

 sandstones, see Appendix to this memoir. 



t At the suggestion of our friend Mr. Warburton, and on the more recent authority of Von 



