THE GEOLOGY OE HELSOH. 
104 
those hills. And it is a fact that the first gold in this Province 
was discovered in a stream which cuts through this diluvium.^ 
I refer to the Motueka diggings, in Pig Valley, at the foot of 
the western ranges. I have heard that quite recently. these 
diggings had been resumed with some success. Bearing in 
mind the source from which the gold is derived, I think it 
likely that the nearer to the western ranges the richer will be 
the diluvium ; but it is at the same time doubtful if it is rich 
enough, for any extent, to be of much consequence. 
I have had many questions put to me with regard to the 
origin and character of the Nelson Boulderbank. I have not 
time to give such an explanation of it as X should w ish to 
present to you. The boulders of winch it consists are entirely 
syenite, and the same rock is found on the precipitous bluff 
which abuts upon the sea beyond Drumduan. The source is 
thus explained:—Fragments are constantly falling from the 
cliffs, and the action of the heavy northerly swell, combined 
with a strong current, takes them towards the south. The 
reason of their being deposited on the existing line is, that in 
all probability a submarine reef underlies them, of which the 
Arrow Bock, in the entrance of the Nelson Harbour, may be 
regarded as the southern termination. This supposition is 
strengthened by the fact of the Arrow Bock being of the same 
altered schists as occur immediately to the south of the 
syenite. 
Before concluding, I wish to make a few remarks upon 
Volcanic Formations in the Province, and upon some general 
matters. 
(5.) Volcanic Formations. 
Although there are no signs of a volcanic action still going 
on in the Middle Island, as far as regards active volcanoes, 
solfataras, and fumaroles, like those in the Northern Island, 
we have at the same time plenty of proof that volcanic action 
has not been less powerful in the Middle Island than in the 
Northern. 
I have not had an opportunity of visiting the volcanic 
districts of this island'; but still, feeling that I should make 
some remarks upon this subject, I will endeavour to explain 
the opinion I have formed from specimens and communications. 
