GEOLOGICAL FORMATIONS NEAR EMBLETON 65 



can be reduced, by the chemical action of surface waters 

 charged with the Humus acids, to the friable, rusty-looking 

 compound one sees close to the surface. The tendency of the 

 dolerite to decompose into rusty, spheroidal masses, shell 

 within shell, often with a central ball of blue rock, is very well 

 exhibited in this quarry. It may be well to mention in this 

 connection that plants appropriate only the CO^ which is mixed 

 with atmospheric air, and take none from water; while rocks 

 absorb none of the dry gas, and take up only that which is in 

 the form of aqueous solutions. This is true of Carbonic Acid and 

 also of the numerous acids of the Humus acid series, of which 

 Carbonic Acid is the ultimate terra. Each ton of dolerite, 

 which would be represented by a cube of that rock about two 

 feet six by the side, in undergoing decomposition, withdraws 

 from the atmosphere 132 lbs., or about a hundredweight and 

 quarter, of carbon. One is rather apt to forget this important 

 fact, and I think most people fail to realise the contest that 

 is always going on, between plants on the one hand and 

 rocks on the other, for the available carbonic acid present at 

 the bottom of the atmosphere. 



A little to the East of Embleton glacial markings may be 

 seen upon the surface of the dolerite. Most of these, as is 

 usual in the maritime area of this part of England, run 

 roughly parallel to the coast, or S.S.E. 



On the shore, about a mile to the East of Embleton, may be 

 seen one or more of the later raised beaches irregularly covered 

 near the sea by mounds of blown sand, between which are 

 many small land-locked hollows. When the Club visited these 

 places the turf was decorated in all directions by Geranium 

 sanguiyienm. On the shore, about a quarter of a mile Northwest 

 of Dunstanborough Castle, the Eight Fathoms (or Underset) 

 Limestone is well exposed. At this point it forms the well- 

 known "Saddle Rock," which has attracted a considerable 

 amount of attention on account of its singular features. On 

 the occasion of the visit of the Club, I expressed the opinion 

 that the Saddle Eock was crumpled into its present form by some 

 agent ^Wiich had operated at the surface, and that it had been 

 forced into its present folded state by the steady thrust exerted 

 by the land ice to which the above-mentioned glacial markings 

 are due, and which slowly roove4 ip ft Soi^tb-eai^ter]^ direction 



