292 Transactions.—Geology. 
I have come to the conclusion that at a time when the present entrance to 
the harbour was closed, and when Port Nicholson was a fresh-water lake, the 
boulders of the isthmus mark a river bar—not a bar at the mouth of the river, 
but a bar at the foot of a pool or lake and above a rapid—probably accumulated 
against a ridge of harder rocks, That this bar must have been re-arranged 
and altered by the sea at the time when the land was depressed some fifteen 
feet below its present level is sufficiently obvious, and accounts for its present 
appearance as having been latterly a marine boulder bank, under somewhat 
similar conditions to that at Napier, although different as lying between two 
ys. 
When we consider the matter fully, it seems a necessity that Port Nicholson 
must have been formerly a fresh-water lake. The borings taken from the 
wharf showed the remains of land vegetation at a considerable depth. There 
One feature is, I think, conclusive as to a certain amount of elevation, viz., 
the present entrance of the harbour. From the remains of Barrett Reef and 
chiefly by denudation. N ow, it is impossible to suppose this to have been 
done by the ebb and flow of the tide. The requisite effect is to be easily 
accounted for by supposing Port Nicholson to have been a fresh-water lake with 
an outlet in Evans Bay. From the erosion of the coast line the locality of the 
even now become a fresh-water lake, with an outlet in Evans Bay ; and taking 
the mean elevation of the isthmus at fourteen feet above high-water mark, and 
supposing a depth of stream of only five feet, the waters of the harbour or 
lake would be raised so as to submerge a large part of the Hutt Valley. 
On the other hand, taking the mean depth of the harbour and entrance at 
ten fathoms, if we suppose a rise of the land of sixty to seventy feet, we should 
have a fresh-water lake, although of diminished area, even with the present 
No strata of marine origin appear to be found in the Hutt Valley. Had 
