116 KERRERA. OEOLOGY. 



may possibly be as well known to the reader as to the 

 writer of this description. 



The simplest and most ordinary substance in this series 

 is a red schistose sandstone, resembling that which occurs 

 among the multiform beds of the lowest red sandstone 

 in this country. With others, I was at first inclined 

 to suppose that this alone was the usual red sandstone ; 

 and that it was distinct from the grey sandstoe and 

 conglomerate that follow it, which have been considered 

 as local rocks dependent on the trap ; though not inclined, 

 with those observers, to consider this rock a trap tuff, 

 as such local conglomerates have been called. That 

 opinion is erroneous and the distinction unfounded; the 

 whole series, whether red or grey, fine or conglomerated, 

 bearing a rigid analogy to the common red sandstone 

 series of other places; differing from it only in com- 

 position, in consequence of the peculiar nature of the ori- 

 ginal rocks from which it has been formed. 



The red portion differs in no respect from the most 

 common varieties of this rock, consisting of quartz with 

 an admixture of red ferruginous clay and mica; occa- 

 sionally also containing undecomposed grains of felspar. 

 Though it immediately succeeds the schist in some places, 

 in others it alternates with the grey sandstone in such a 

 manner that this occasionally becomes the lowest in posi- 

 tion. It forms beds of variable thickness, sometimes, as 

 above remarked, tending to the schistose structure, at 

 others very massive ; occasionally of a fine texture, in other 

 places gravelly, and in many, presenting the conglomerate 

 character in a very striking manner, from the great size of 

 the imbedded fragments. These several varieties are every 

 where intermixed, as is usual in the red sandstone ; the one 

 succeeding the other without any regular order, and even 

 the individual bed varying in the course of its lateral 

 progress. In all cases however, the base of the con- 

 glomerate is the same as the fine sandstone, the differences 





