588 
and to contain no fist. At any rate, we saw none. Neither did w*e see any water-fowl, 
which are said also never to visit the lake. There was nothing in the taste of the water 
to account for this absence of life, if it be a fact. The highest flood-marks we saw were 
about three feet above the water. It must he remembered that we visited the lake at 
the latter end of an unusually protracted drought. The slight variation of level might 
be accounted for by the fall of rain on the lake and its banks on the one hand, balanced 
by evaporation and leakage on the other. 
The “Volcanic Hill”* marked on the map in “ Pinnacle Pocket,” on the right bank 
of the Barron, between the mouths of Leslie and Petersen’s Creeks, stands about 200 feet 
above the level of the basaltic tableland, and is composed of a highly scoriaceous basalt 
very rich in olivine. There are said to be several similar hills in the jungle in the neigh- 
bourhood, and in all probability they are “necks” or “plugs” — f.e., volcanic orifices 
filled up with solidified basaltic lava. 
It is interesting to find two volcanic craters almost side by side, the one filled up 
with hard lava-form rock, and the other surrounded by friable ejected ash and forming 
a crater-lake. It is just possible that in spite of their proximity they may be of different 
ages, the “ plug” belonging to the “ Older ” and the “ crater-lake ” to the “ Newer ” 
Volcanic series. Or they may even both belong to the latter. 
On the Russell River, south of Mount Bartle Frere, gold is obtained in considerable 
quantities, mixed with stream tin ore and (rare) platinum, from gravelly drifts which 
rest on slates and schists, and are overlaid by horizontal beds of basalt. The basalt is 
one of many denuded fragments which once formed a part of the immense plateau 
extending southward from the Mulgrave to the heads of the North .lohnstone and west- 
ward to near Herberton. In Messrs. Clarke and Joss’s Claim, which is the south-eastmost 
working, the edge of the basalt is seen to overlie a siliceous sandy silt permeated with 
iron peroxide. The silt shows alternate layers of coarser and finer material, and is in 
places eross-hedded. It rests on a “ washdirt” mainly composed of well-rounded quartz 
boulders. There are no basalt stones in the wash, and no boulders of granite. 
The latter circumstance is hard to account for in a valley where granite w 
frequently to be met with in situ. The washdirt varies in this claim from 2 inches to 
30 inches in thickness. Between the washdirt and the slaty bed-rock a very fine white 
siliceous silt, a few inches in thickness, generally intervenes. The fact that this silt is 
traversed by a few thin veins of quartz renders it probable that the sand was formerly 
cemented into a sandstone, but has lost its cement after the formation of the quartz 
veins. 
The outcrop of the washdirt has been opened out along the south-eastern and 
north-eastern side, and a tunnel has been driven through the washdirt for 135 feet from 
S. 10° E. to N. 10° "VV. This tunnel is connected with another running 50 feet 
to the east. Another tunnel has been driven 70 feet to W. 10° S. from O' 
point on the hillside 120 feet N.W. of the northern end of the long tunnel. At the 
inner end of the 70-foet tunnel the slate bottom rises up and the basalt comes into direct 
contact with it. This tunnel is only used as a reservoir, from which the water is 
conducted to the tip at the end of a tramway leading from the mouth of the long tunnel. 
The basalt is in some places at least forty feet thick, but is often decomposed throughout 
its entire thickness. It rests, as seen in some places (of which there is an example m 
an opening near the south corner of the claim), directly on the washdirt, the absence of 
the upper silt proving that it was poured out over an uneven and denuded bottom- 
* “ Volcanic ” is scarcely distinctive enough in the midst of a volcanic region, but the “ hill ” in the 
midst of the basaltic plateau is a conspicuous feature. 
