TRANSACTIONS OF THE SECTIONS. ὦ 97 
broken and picturesqne gorges) which he had witnessed along the banks of the 
Sichon and around the castle of Busset. 
Towering masses of dark gray and reddish quartziferous porphyry, with veinstones 
of quartz (occasionally very like granite), have there penetrated in every direction the 
mutilated schists and grits, which can notwithstanding be recognized as fragments of 
the very same strata as those of the Sichon; although the graywacke schist has in 
many parts become a crystalline, amphibolic schist, and the grit has been converted 
into quartz rock. 
In examining the granitic and schistose chain of the west of the Limagne, the author 
was disposed to think that parts of it (particalarly near Ebreuil) will eventually 
be assigned to the paleozoic deposits also; but the engagement to return to the 
meeting of the British Association prevented the completion of researches to establish 
this point. 
In the mean time he calls attention to the importance of the discovery of Lower 
Carboniferous fossils in rocks of so crystalline a nature as those of the chain of the 
Forez. It has long been known that small but true coal-fields occur in many parts of 
Central France, some of which the author described long ago in conjunction with 
Sir C, Lyell; bnt at that time no geologist could have dared to think that any pertion 
of the crystalline or slaty schists of the adjacent mountains could also pertain to 
the Carboniferous system. Yet such is the fact. For independent of this discovery 
in the chain of the Forez, M. de Vernenil had observed, that the “ Producti” and 
other fossils found at Regny, near Roanne, in a system of hills parallel to the Forez, 
and of very similar composition, unquestionably placed such rocks in the Carboni- 
ferous or Mountain Limestone group of the Carboniferous system. These facts, as 
well as the occurrence of numerous true carboniferous Producti at Sablé in Britanny, 
where these rocks are unconformable to overlying coal-fields, have, it is understood, 
induced M. Elie de Beaumont to renounce an opinion which he fermerly entertained, 
in considering the inclined formations as belonging to a different natural group to 
those which are horizontal. In their exploration of the palzozoic rocks of Germany, 
Professor Sedgwick and Sir R. Murchison long ago indicated that the true carbo- 
niferous limestone with large Producti, near Hof, had been raised up conformably 
with underlying Devonian and Silurian rocks (see Trans. Geol. Soc. New Ser. vol. vi. 
p. 298. pl. 23. f. 15), the adjacent Bohemian coal being horizontal. Although this 
indisputable fact, since confirmed by a subsequent visit to the tract, was at the time 
received incredulously, it is now sustained by independent evidence in France. The 
conclusion, therefore, is, that very powerful continental dislocations have operated 
both in Germany and France, after the close of the deposits of the mountain or car- 
boniferous limestone, and before the accumulation of the great overlying coal-fields. 
Seeing the facts in this light, and M. Elie de Beaumont having now introduced a 
new epoch of disturbance into his classification, Sir Roderick considered this subject 
to be one eminently meriting discussion at a meeting of the British Association, in 
order to test the application of such periods of dislocation to the carboniferous series 
of England, Scotland and Ireland, it being understood that in many tracts of Britain 
no apparent unconformability had yet been observed between the carboniferous lime- 
stone and the overlying coal-fields. The existence of such dislocations in some 
regions, and their non-occurrence in others, bear out, he maintains, the view he has 
long contended for, that all dislocations are local only when viewed in a general sense. 
Phznomena, for example, which are true in France and Central Germany, do not 
apply to Russia or the British Isles. 
Review of the Labours of ΜΙ. Barrande in preparing his important work “ The 
Silurian System of Bohemia.” By Sir Ropericx Impey Murcuison, 
G.C.St.S., PRS. President of the Section. 
The Silurian rocks of Bohemia offer, on the whole, a striking analogy to those of 
the classical region or type of the same deposits in England and Wales. The same 
two chief divisions, though easily distinguished from each other, as in the British Isles, 
by local circumstances, are in the one country, as in the other, so bound up together, 
as in reality to constitute, in the opinion of M. Barrande, one inseparable ‘system’ 
only. The lower Silurian rocks reposing upon granite and gneiss, are composed of 
1850. H 
