366 C. CALL AW AY ON" THE NEWEK GUSTEISSIC 



and the old gneiss is brought against the Quartzite. Limestone is 

 not a rock which thins out from 100 feet to nothing within 50 

 yards, and then as abruptly reappears. Dislocation, not deposition, 

 can account for sucn facts. But walking over the zone between 

 the Quartzite and the Caledonian, the proof of dislocation is abso- 

 lutely convincing. The ground is literally a pavement of fragments. 

 Blocks of quartzite, dolomite, and Hebridean are fitted in together 

 without any principle of arrangement. In one spot, for example, 

 passing along the strike of the Hebridean, we come to dolomite, 

 then on to Hebridean, and then to quartzite. 



In this locality some soft shale occurs in association with the 

 quartzite ; and in one place the shale is ra in actual contact with He- 

 bridean. If what I have called " Hebridean " is igneous, why was 

 not this shale altered ? Or if this Hebridean is a part of the 

 " Lower Silurian " subsequently metamorphosed, why should the 

 metamorphosing agent have acted upon grit, and left shale in con- 

 tact with the grit unaffected ? 



4. Section from Ullapool over the high ground to the E.N.E. 



This section was drawn with special care, the heights being taken 

 with the aneroid. The base of the Quartzite was reached at 210 

 feet above the sea, and the Caledonian at 700. The Assynt series 

 was unbroken up to the $a-Ztere Wa-quartzite (660 feet), which sud- 

 denly rose fnom its normal dip of 15° to 45°, and was succeeded by 

 the Hebridean, which here is a reddish granitoidite. The dip of 

 the Assynt rock is to the E.1ST.E. Beyond the old gneiss the Cale- 

 donian (Hope series) is seen dipping to the E.S.E. at 10°. The 

 abrupt plunging-down of the $#Ziter^a- quartzite would suggest a 

 fault, even were there no other evidence to show that the Dolomite 

 has been entirely thrown out. It is also to be noted that the strike 

 of the Caledonian diverges from that of the Assynt group by 45°. 



5. Section along the south side of the Ullapool river, W. to E. 



This line runs about a mile north of the last. Walking up the 

 valley, we first notice a fault in the Quartzite, the Torridon being 

 thrown up to the east. Then we have the succession of the Assynt 

 series nearly complete, the Dolomite approaching its maximum 

 thickness of 300 feet. The upper part is probably cut out ; for, 

 above the narrow gorge which the river has excavated in this rock, 

 the Dolomite is abruptly succeeded by the Torridon, again faulted 

 up, the junction being very well defined. Along the line of contact 

 deep trenches are hollowed out. Beyond the Torridon we come to 

 the granitoid gneiss (Hebridean) ; and at the west end of Loch Auchall 

 we reach the Caledonian. 



6. Section along the north side of the Ullapool river, W. to E. 



The succession in the lower part is similar to the last, the fault 

 in the Quartzite being very clearly seen. But further east there is 

 a remarkable difference. Though the two sections are parallel at 

 a distance of little over a quarter of a mile, both the Dolomite and 



