MINERALOGY OF THE REDHEAD. S4& 



bability, owe their origin to the cause which I 

 have here pointed out. 



The strata of sandstone in this district, observe 

 the general direction and inclination of the beds 

 to which they belong, unless in a few instances, 

 where the structure of individual strata presents 

 marks of irregularity of deposition. Thus, to 

 the south of the harbour of Aberbrothick, the 

 thin laminae which form a stratum, are often un« / 

 ijonformable among themselves, while the roof 

 ind pavement of the bed are parallel to each 

 <^ther. Appearances of this kind are very common 

 in every sandstone-rock, and in every alluvial hill 

 (^f water-borne sand. In the last of these, such 

 Appearances have been occasioned by irregularities 

 in the motion of the fluid which gave the par- 

 tjicles their arrangement. May we not infer the 

 agency of a similar cause in the production of 

 similar appearances in strata of sandstone ? 



In one instance, I observed a little irregularity 

 to prevail, not only in the dip, but al$o in the di- 

 rection of the strata, but which irregularity, in 

 the great scale, did not affect the general disposi- 

 tion. To the south of the last-mentioned place, 

 strata of soft slaty sandstone stretch E. by N. and 

 W. by S., and dip at angle of 20° S. by E. When 

 proceeding in this direction, they are interrupted 

 by other strata of sandstone, coarser and more 

 compact, which stretch from S. S. W. to N.N.E., 

 and dip at an angle of 50^ to the E. S. E. These 

 cross strata, which extend in their line of bear- 



