622 ON tM RED SANDSTONE OF fUt 



stricts, the trap and porphyry rocks occupy thiPe^- 

 fourths of the whole mass ; yet these rocks may 

 be wanting without their absence affecting the ge- 

 neral characters of the red sandstone formation < 

 In the same manner, the various subordinate beds 

 in the clay-slate, such as whet-slate, drawing-slate, 

 and alum-slate, may be wanting, and still the cha- 

 racters of the clay-slate, as a distinct formation^ 

 temain. 



In several places on the sea coast, as neat the 

 mouth of the North Esk, and in the tract ex^ 

 tending from Montrose to Lunan Bay, where the 

 subordinate trap and porphyry rocks prevail, there 

 are striking rugged sea cliffs. 



The red sandstone rests on Primitive rocks, or 

 on rocks of the Transition class. It is distinctly 

 stratified, and the strata vary from the horizontal 

 to the nearly perpendicular position. The strata 

 are sometimes waved, but are more frequently 

 straight. Sometimes vertical strata are to be seen 

 meeting others which are in a horizontal posi- 

 tion, and occasionally vertical strata appear to be 

 contained in great masses of nearly horizontal or 

 slightly inclined strata. Occasionally the strata 

 in a small district appear disposed in every pos- 

 sible position ; and at first sight suggest to us the 

 idea either of great original inequalities, or of 

 violent action on the strata after their formation^ 

 but which, upon more careful examination and 

 consideration, would seem rather to intimate that 



