1862.] 



HARKNESS METAMORPHlC ROCKS. 



337 



On this occasion I endeavoured to make out the relation of these 

 quartz -rocks to the deposits which are so fully exhibited in Suther- 

 land, and which form the upper or flaggy gneiss of Murchison*. 



Fig. 2. — Section from Berridale to Strath Naver. Length 30 miles. 



S.E. N.W. 



f. Grranite. 



e. Old Red Sandstone. 



d. Flaggy gneiss. 



c. Grranite and gneiss. 



h. Gneiss and grey quartz-rock. 



a. White quartz-rock. 



I here purpose to describe the rocks which occur in a traverse 

 from the coast at Berridale, in Caithness, to Strath Naver, in Suther- 

 land, the route being from the S.E. to the N.W. — a course almost 

 directly across the strike of the metamorphic rocks, not only of this 

 district, but also of those of the whole of Sutherland, with some 

 slight local exceptions. Having Hkewise examined some of the 

 stream-courses to the south of the Scarabin range, I shall allude to 

 them as illustrative of the sequence of the strata which compose the 

 metamorphic rocks of this district. 



Commencing on the coast, we have, in the Langwell Burn, from its 

 entrance into the sea to the Turnel rock, brown flags of the Old 

 Red series, dipping N.IS'.E., and passing downward into the inferior 

 conglomerates. A mass of granite then occurs, which is a portion 

 of that forming the Ord of Caithness extended northward, and 

 it cuts off the Old Bed series from the metamorphic rocks on 

 the N.W. at this locality. This granite continues for a short 

 distance to Bean-na-aigiesh, where the metamorphic strata exhibit 

 themselves. Here the beds consist of grey quartz-rocks which have 

 a S.S.E. dip at 45° ; and quartz-rocks of a similar character, and 

 having the same inclination, are seen in the Langwell Bum at Alt- 

 di-ba. The same features, as concerns lithological nature and dip, 

 are seen in the Alt Begg to Tolbegg ; and on the sides of Salvaich, 

 one of the Scarabins, to the west of Alt Begg, grey quartz-rocks 

 occur with the same inclination. The fine isolated Old Red 



* On this occasion I was provided by Sir Roderick Murchison with his obser- 

 vations as recorded on the Duke of Sutherland's map of this county, and also the 

 notes of Sir Roderick which had reference to this district ; he also very kindly 

 procured for me a note from the Right Honourable the Speaker of the House of 

 Commons to his people at Langwell, and by this means I was enabled to avail 

 myself of the services of Donald Ross, gamekeeper to His Grace the Duke of 

 Portland, who accompanied me, not only over the Scarabins, but also into Strath 

 Beg to Achintoul. 



