54 
west direction as. hut narrower than those of the vSound)* ** , appar- 
ently formerly existed as the entrances to Princess Royal Har- 
bour.^* So far as the Sound channels arc concerned, we have 
sug'gestcd above that the old united King-Kalian River probably 
passed through the south channel, and thus the latter becomes 
intelligilde. but the origin of the Princess Royal channels is not 
clear, as no present stream can be suggested as having occupied 
any one of those channels prior to submergence. 
Both on the mainland and island coasts of the harbours, cliffs 
appear to have been little cut by the sea, thus ap])arently emphasising 
the comparatively recent drowning of the land: but in this con- 
nexion. it must he remembered that the mode of weathering of the 
granite into rounded masses by exfoliation, would tend to keep the 
cliffs relatively lou by the constant slipping into the sea of the 
large onion-like Ikikes of rocks above the sea-cut clilYs, thereby 
reducing the height of the latter. 
On the ocean coast Itetween Bald Head and Torbay Inlet, the 
cliffs are high and steep, and the coast line, despite certain promon- 
tories of granite, is on the whole very regular and unindented, 
suggesting strongly that marine abrasion has been at work for a 
considerable peirod of time. The nature and structure of the rocks 
must however, as regards this point, he taken into consideration. 
As already indicated, the surface rocks of the Darwin Ridge are 
the cjasta. limestones, plastering and covering over, as con.solidateH 
sand dunes, the old granite. The action of the wind in building 
up sand dimes along a coast almost invariably smooths the outline 
jf that coast, and hence it may be concluded that the present form 
of the coast in question is due to this cause. 'I'his land must how- 
ever, in the alisence of direct evidence to the contrary, be regarded 
as having taken part in the depression which caused the drowning 
of the valleys and plains, and consequently the coast line must 
have extended farther south. This raises the question as to when 
the sands which now form the limestone were built up. If we regard 
them (and therefore the resulting limestone) as of later occur- 
rence than the drowning of the valleys, that is a sufficient explana- 
tion of the present contour of the coast: hut the limestone, as 
Hmesione. although it is still forming as shown above, certainly 
appears for the most part to l)e older than the loose sands which 
form the various bars aliout the large harbours, and which rc])resent 
tlic deposits since the last known submergence. The formation 
in large part of the limestone may therefore probably he regarded 
as i)rior to such submergence, although the point cannot at present 
*In acldition to the «^reement in number and direciion between the two 
sets of channels, the most southerly of the three is in each case, the widest. 
**The causes of the disappearance of two of these channels are later 
stated. 
