42 MOUNTAIN AND MOORLAND 



very often like pyramids or like pyramids without their 

 tops. They tend to show terraces, steps, or corbels, 

 corresponding to the sedimentary beds. They often 

 look like castles and fortresses, as in the picturesque 

 sandstone of Saxon Switzerland. They are table- 

 mountains and pyramids in the dissected plateau of 

 the Sahara. The character of the result will vary with 

 the character of the sedimentary rocks and with the 

 nature of the dissecting instruments whether warmth 

 and cold, or rain and snow, or the wind-driven grit and 

 sand. The dissections that have been made in the 

 canon region of Colorado are famous, and nearer 

 home the basalt rocks of the Inner Hebrides and 

 Antrim are the residues of a great plateau of accumu- 

 lation. Most of the escarpment hills of Central Eng- 

 land illustrate the carving out of plateaus with inclined 

 strata. 



But Relict mountains may also be carved out of 

 plateaus of erosion. This is very largely the case with 

 the mountains of the Highlands of Scotland, such as 

 the Cairngorms. A great tableland, consisting funda- 

 mentally of the remains of very ancient Tectonic or 

 Original ranges, has been carved into the well-known 

 " Bens." These, as Professor Geikie points out, are 

 very generally massive and round-shouldered, not like 

 the peaks and " horns " of the Alps. They are usually 

 in groups and not differing much from one another in 

 height. "One can hardly doubt that such relation- 

 ship is due to the simple fact that the mountains are 

 the remnants of a tableland, the surface of which is 

 indicated approximately by the summits of the several 

 mountain-masses. If we in imagination fill up the 

 valleys, we shall in some measure restore the general 



