64 Scientific Intelligence. 
valley on the west, then bending back on itself, winding round 
the north slope of Draim Tun i, and entering ‘Loch Eriboll in 
Heilim Bay. It reappears at t the base of Crag-na-Faolinn, and 
has i traced still farther to the south, while northward it can 
where is in reality the Archean gneiss is evident, for two rea- 
sons. First, its lithological characters agree ee those of the 
crystalline hornblendie gneiss and pink granitoid gneiss, with 
lenticular veins of hornblende-rock = kernels of cleavable horn- 
blende, hile a massive veins of pink matite are well developed. 
The soft greenish mineral laaatintetie ?) already mentioned as 
characteristic of the gneiss, where now or lately covered wit 
quartzite, occurs here in the pegmatites, and veins of epidosite 
are abundant. Second, at various localities the brecciated con- 
glomerate ee false-bedded quartzite at the base of the Silurian 
r more than a mile. There can be no doubt, therefore, that this 
mass is really a fragment of the old platform of Archzan rocks 
on which the Silurian strata were deposited. 
But all these evidences of displacement are merely the precur- 
sors of a still more heed thrust-plane, which has , been traced 
continuously from the ~~ _ of Whitten Head to the crest of 
Crag-na-Faolinn, and a rvals for many miles to the south- 
ward into the Assynt ¢ ze Binh w 
One final feature of the Durness and Eriboll area remains to 
north-northeast and south. southwest, while another, which appears 
to be newer, trends more or less at right angles to these. B 
Durness Basin is due - two normal step-faults, one of which lets 
down the quartzites more than 1,200 feet, while the other brings 
the whole Silurian Bake down to the sea- leve 1” 
sie 
