Geological OLservatmis, IS,") 



stone, which \n so jtiany districts is associated with and lies upon 

 it, is tlie first fluetz limestone. The bituminous marl-slate which 

 is said to characterize this particular formation, I have found, in 

 its usual situation under the limestone, in the neighbourhood of 

 Bristol. But any thing I can say will be of far less consequence 

 rb.an the opinion of Professor Jameson, who allows me to state 

 that, as far as iie can judge from the description I have given 

 and the specimens 1 have shown him, he considers the red sand- 

 stone and mountain limestone as members of the first flcEtz for- 

 mation. 



It is a point vet to be ascertained, v.liether the limestone as- 

 sociated with the coal-field of Derbyshire is to be considered as 

 ))clonging to the fltetz or transition series. The red sandstone 

 which so commonly accompanies the mountain limestone in 

 otlier parts of England, is here wanting, and its constant alterna-^ 

 tion with amygdaloid dis-tinguishes it from the mountain lime-' 

 stone of other quarters. The strata too, or measures accom- 

 panving the coal, as far as I can make out from the perplexing 

 language ami confused description of those who have seen most 

 of the Derbyshire coal-field, seem to be quite different from 

 tliose usually associated with the coal in England. 



Dr. Prichard, in a late numl)er of the Annals of Philosophy, 

 has endeavoured to show that the mountain limestone belongs 

 to the transition series ; because the organic remains which it 

 contains are similar to those which are assigned to transition 

 rocks. And hence he concludes that the first floetz limestone 

 of Werner, to winch another description of fossils belongs, is 

 more recent than tlie rocks of the coal formations in England. 

 Tlie fact, however, that the fossils of the mountain and transi- 

 tion limestone are of the same description, does not appear to 

 me to warrant the conclusion which he wishes lo deduce from 

 it ; for, if the mountain limestone be transition, it is very evident 

 that the red sandstone which lies under it must also be transi- 

 tion. But v,-e have seen, and he himself allows it, that this rock 



Tills opinion Mr. Jameson extends to many rocks wliicli appear to exhibit 

 marks of mccliat)ical action, as gray wacke, trap tu 3", breccia, &c.; and I 

 think it is only necrbsary to see the specimens and hear tlie argument 

 ^vllicl^ he acivniices in support of this opinion, lo be convinced of the trutii 

 of it. ])r. KidiJ in his recent pjblicatiij;), I find, entertains the same opi- 

 nion, and lias advanced many ingenious arguments in favour of it, appa- 

 rently vvithont beina; a'vare that it liad long before been projiosed by Pro- 

 fessor Jameson, in ins paper on Con>;lomerate Rocks, published in the 

 Wernerian Transactions, and has also been announced in Dr. TI)omson's 

 Annals of Philosophy. This appears the more strant;e, because Dr. Kidd 

 :.< oms to have read every author from whom he could derive information 

 ■ •M <;foli>uicai subjects, and of course covild i'ot bv.c have riven the VVer- 

 tu-uixu Transacliyns 9 diligent perusal. 



agrees 



