403 
NOTES ON BORING OPERATIONS IN SEARCH OF 
COAL IN TASMANTA, 1884. (Continued.) 
By T. Sreruess, M.A., F.G.S. 
[Read November 16, 1885.] 
In continuation of the short paper read last year on the 
works then in operation at Cascades, Hobart, and at Tarleton, 
I now lay before the Society the records of boring with the 
diamond drills, together with a few remarks on the results. 
I have, on several occasions, pointed out the extreme im- 
probability of the discovery of coal in either locality, but 
there were many who held a different opinion, and it was 
well that the question should be set at rest 
The work at the Cascades was much impeded by the 
“‘jointy” character of the rock, which from tae surface down- 
wards showed uvmistakeable signs of disturbance, such as 
might be expected from the presence of great faults crossing 
the valley on both sides and from the proximity of eruptive 
rocks. Circumstances prevented me from visiting the place 
from the beginning of March until after the works had been 
stopped, but I was informed from time to time of what was 
being done. In the month of August I was informed that 
the drill had struck “ granite,” and a glance at a core, sent to 
me by order of the Minister of Lands, enabled me to report 
that the trap rock had been reached, and that further ex- 
ploration was useless. After the stoppage of the work I 
ascertained, by inquiry and by examination of the cores 
which had been preserved, that the igneous rock, which is the 
common diabase or “ greenstone”’ of the neighbourhood, had 
been first struck by the drill between 509 and 519ft. from the 
surface, and had therefore been penetrated to a depth of 
about LOOft. before its true character was recognised. That 
it is here an intrusive rock, and therefore newer than the 
Upper Paleozoic beds, which are in contact with and partly 
overlie it, I have no doubt at all; the superficial evidence of 
local disturbance, the joints and fissures filled in with calcite 
and pyrites, the alteration noticeable in various bands, which 
differs according to their lithological character, and is in 
exact conformity with that which is always associated 
with the presence of intrusive rocks, point unmistakeably to 
this conclusion. I regret to find that on this point I am 
compelled to disagree entirely with my friend, Mr. Johnston, 
who, in a paper recently read before the Society, cites this as 
an instance of the priority of the igneous rock to the sedi- 
mentary beds with which it is associated. 
