BOCKS OF THE NORTHERN HIGHLANDS. 385 



of the gneiss is parallel to the loch, while the underlying quartzite 

 and dolomite strike across the loch. 



The discordance between the gneiss and the rocks which overlie is 

 equally marked, as previously described. 



This remarkable ground throws new light upon the similar sections 

 further south. • The valley having been cut across the strike of the 

 Assynt series, we see the internal structure of the overthrow. The 

 curvature, accompanied by excessive crushing, so clearly seen at the 

 head of the loch, is just what we should expect to find if the beds 

 were broken off, and then pushed laterally by the force which threw 

 over the gneiss. The masses of " Upper " Quartzite up the glen are 

 simply undenuded fragments of the Assynt rocks remaining on the 

 east side of the fault. 



The older and newer groups hold similar relations to each other 

 for several miles to the north. On Loch Glen Dhu the Assynt rocks, 

 smashed into fragments, are overlain by the gneiss striking at a dis- 

 cordant angle. 



I have not examined the east end of the section on Loch More, 

 described with such different interpretations by Murchison and by 

 Nicol; but at the western end I found the Quartzite and Brown Flags 

 succeeded by the granitoid gneiss of Craig Dhu, no signs of actual 

 overlie being visible. JSicoPs north-westerly dip of the quartzite 

 away from the " igneous rock " is, I fear, a mere matter of joint- 

 ing. The region between this point and Loch Emboli I have not 

 studied. 



Ground betiveen Coniveall and Glen Coul. — The dislocation which 

 passes through the Balloch follows the western escarpment of Coni- 

 veall, and is apparently continuous along the west of Ben Uarran 

 with the Poulan-drein fault, unless, indeed, the throw dies out at the 

 sharp curve near Glenbain. On this line the proof of lateral thrust 

 is similar to that described further south, as seen in the overthrown 

 folds of quartzite at the west end of Ben Uarran, in Cnoc-an-drein, 

 and on the Burn of Calda, though, of course, the action of the force 

 is much weaker. I believe the fault passes from Calda Burn along 

 the west side of Glasven ; but the country is too obscured by debris 

 to furnish other than inferential evidence. From Glasven the dislo- 

 cation is continued by Loch na Gamvich to Loch Glen Coul. 



Section on Camaloch. — The Hebridean which appears here lies four 

 miles to the west of Scounan, the nearest point of the main mass of 

 " Logan Bock." The rocks are largely covered ; but the following 

 facts are fairly clear. The section is from west to east. On the 

 stream which falls into Camaloch from Loch a' Chroisg the Quartzite, 

 resting on Torridon, dips at a low angle to the east, and after a short 

 interval there is a slight exposure of Brown Flags in their usual 

 place. Drift then hides the ground, and the next rock seen is 

 quartzite of the seamy type, with bits of red felspar and associated 

 " porphyry," overlain by Hebridean gneiss. Following the strike 

 down to the shore, the Quartzite is seen to be excessively shattered 

 and contorted. There is in this section evidence of inversion, gneiss 



