the Primary Rocks and the Oolitic Series in the North of Scotland. 



Ib'o 



A short distance to the south of Duncansby Head, and immediately opposite 

 the detached pinnacles called the Stacks of Duncansby, the red sandstone re- 

 appears, and is continued for about a mile, when it is cut off by a fault which 

 ag'ain brings up the lower flagstone group. From thence to the granite of 

 the Ord of Caithness, the newer sandstone (with the exception of a small 

 patch on the north side of Freswick Bay) is not again seen on the coast; and 

 the beds, as was before stated, are exhibited in the descending order. 



2nd. Descending Series exhibited in the Coast Section from the Upper Sand- 

 stone to the Granite of the Ord. 



A little to the south of the last-mentioned fault, the cliffs exhibit one of the 

 most curious of the indentations abounding- on this coast. The sea washes 

 far into a deep straight-cut reservoir, of about 250 or 300 yards in leno-tii, 

 nearly 300 feet in depth, and from 40 to 50 feet in width. Three entrances 

 lead from the sea to this dark creek, two of which are open clefts, and the 

 third is a tunnel of about 20 feet in width, and 40 feet in height ; having 

 therefore above 200 feet of solid rock for its roof. These cliffs lower s-ra- 

 dually to the sandy beach of Freswick ; and, after a short reappearance south 

 of that place, where they are chiefly composed of brown, grey, and greenish 

 thin-bedded sandstone alternating with pyritous shale, they again disappear 

 in the large sandy bay of Keiss. 



In the interior of the tracts of country bordering upon the coasts we have 

 been describing-, the strata are obscured by vast expanses of moor and moss ; 

 the only portion of sound ground in many places being close to the cliff, whicli 

 is frequently capped by a belt of verdant turf, which thus affords the only line 

 of road to the traveller. 



At the old castles of Sinclair and Gornigo, there is a good section of tlie 

 stony, dark bluish, calcareous flagstones which are continuous along- the coast, 

 from thence to the cliffs on the south side of Wick. At these places they 

 differ from the fissile calcareous beds of the north coast, chiefly in being less 

 interrupted by alternating masses of grey sandstone, and in being- stronger 

 and more thick-bedded, on which account they are much used in building*. 

 Some of them are micaceous, and they are all highly calcareous. The 

 purer and thicker beds contain a few contemporaneous veins of carbonate of 

 lime, and approach the mineralogical character of some dark beds of tranni- 



* The old castles mentioned in the text, the pier at Wick, and a considerable part of the town, 

 are built of this stone. In the other parts of the coasts, the best building.stone is derived from 

 the strong, alternating beds of grey and brownisii sandstone. The finer beds of the dark cal- 

 careous flagstonej arc commonly used as roofing-slate. 



