342 MINERALOGY OF THE REDHEAD. 



gneiss, mica-slate, quartz, porphyry, greenstone, 

 basalt, and red-sandstone, with interposed layers 

 of fine sand. It sometimes alternates with beds 

 of sand composed of small particles of quartz and 

 felspar, and numerous scales of silvery mica. The 

 gravel is in many places so firmly cemented, 

 that the hand is unable to separate the individual 

 masses, and the particles of sand often cohere, and 

 form a sandstone which can be divided into strata 

 by means of a knife. Sometimes beds of clay oc- 

 cur, which have a laminated structure, and indi- 

 cate a deposition from a fluid but little agi- 

 tated. 



The eastern base of these hills, is truncated, 

 and the intervening space between their extremi- 

 ties and the shore is level, and consists of a soil 

 composed of gravel, mixed with the remains of 

 sea-shells. The lower or southern portion of the 

 Town of Aberbrothick, rests upon strata of sea- 

 borne gravel, mixed with the fragments of seve- 

 ral species of littoral shells. This portion is ele- 

 vated but a few feet above the ordinary rise of 

 spring-tides, and is liable to inundations of the sea 

 during great storms. It appears, that at a former 

 period, a considerable portion of land had been 

 gained from the sea, especially along the coast to 

 the south of the town ; but the currents having 

 changed, Neptune is again resuming his dominion 

 over those tracts which he formerly relinquished, 



