st.johx] PALEOZOIC AEEAS. 479 



same excessive denudation, the northern flank of the range at least 

 bearing a heavy protecting mantle of early Mesozoic strata. However, 

 in the interior portion of the range they are bared in magnificent escarp- 

 ment exposures, the various formations impressing their individual 

 characteristics on the mountain topography. 



The Buffalo Fork Peak uplift has brought to light an equally inter- 

 esting exhibition of the Palaeozoic rocks, and associated with phenomena 

 which may have important bearing on the physical history of the era in 

 this quarter. The quartzite and Quebec Group Hmestones, although 

 holding a prominent place in the stratigraphy, do not attain the same 

 degree of development as do the same deposits in the Teton Eange. 

 And in connection with this attenuation of the upper limestone of the 

 Quebec, there appears to have been no cessation in the deposition of 

 calcareous matter, and the one or two himdred feet of passage limestones 

 intervening between the Quebec and Carboniferous ' deposits, if they 

 prove to be Niagara at all, show the same diminution in the amount of 

 limestone-making materials that were here thrown down upon the sea- 

 bed during that epoch. The Carboniferous, however, apparently attains 

 its usual development, and in the character of its components and 

 lithology the closest agreement obtains with its appearance in the Gros 

 Ventre and Teton Eanges. 



Prom the observations of Dr. Hayden and Professor Bradley, together 

 with such information as was derived during the present season's explor- 

 ations, the following general section of the Palaeozoic series in this 

 district has been prepared ; 



