79 
paddock, with the object of cutting the continuation of the payable washdirt 
worked in the Back Creek. The length of this tunnel is, however, not 
sufficient, as it should be driven about 600 feet. It would be dry ground 
to work, and as the run of wash in the creek and both north and south of 
it so far as worked was profitable, the additional driving should be done. 
The cost would be about 10s. per foot. There is a possible extension of 
the washdirt southward, or up the river for a mile. If once opened up 
it could be worked economically, and a little mining would be a boon to the 
residents, as the ground could be worked in the slack season for farming. 
Paul’s Dyke. 
A few chains south-east from the south-east corner of allotment 6, section 
A, parish of Eurandelong, there is a hill which is about 1,030 feet above sea- 
level. On the top of this hill there is a fault in the Ordovician beds running 
east and west, and dipping south at 85°. In this fault is a reef of crushed 
material mixed with quartz about 1 ft. 3 in. wide. On this reef a little work 
has been done, and a couple of crushings were taken out that are said to have 
yielded half an ounce of gold per ton. About half a mile south-east from 
this point is the junction of the Ordovician with the Buffalo granite mass. 
This appears to be on the western limit of the auriferous belt. If some 
other reefs were discovered it might be worth while to erect a small plant 
to crush for them, but they would probably be of low grade. 
[24.8.10.] 
THE MAMMOTH LODE, GIBBO RIVER. 
By E.J. Dunn , F.G.S., lute Director, Geologicul Survey. 
At a distance of 2J miles north-eastward from King’s, on the Gibbo 
River, the mining track has cut through and exposed a sulphide lode 12 
feet thick. The country rock is slate and sandstone, apparently of Ordo¬ 
vician age. Through this a dyke of quartz porphyry 200 feet thick runs 
in a northerly and southerly direction. There is evidence of sulphides 
being present throughout this dyke material, and the rock is stained reddish 
through oxidation, r but the solid sulphide appears to have aggregated near 
the eastern side of the dyke. Just below the track the river flows at a 
depth of about 60 feet, and on the south bank the sulphide lode is exposed 
and is 40 feet wide. Samples were taken from the exposure on the track 
and also at water-level on the river bank, and these have been assayed. 
Northward this lode does not appear to have been traced, but southward 
it is said to crop out at the head of Turnback Creek, and gossan from the 
outcrop has been shown to me. The gossan is reported as occurring 2 miles 
south of the mining track. Such a strong dyke is likely to be traceable 
through the country for a considerable length, and if it runs northward of 
the Gibbo River it will cut through a mountain over 1,500 feet high. South¬ 
ward from the river the country rises into high hills, so that there would be 
good “ backs ” in this direction. From Benambra a good vehicular road 
exists as far as King’s, and there would be little expense incurred in con¬ 
tinuing it to the Mammoth Lode. The Gibbo River is a strong and ever- 
flowing stream, with rapid current, and it could be utilized for electric 
power purposes. For economical working the site is excellent. Results of 
assays made at the Geological Survey laboratory are as follow :— 
Gold, from trace to 6 gr. per ton. 
Silver, from trace to 6 oz. 17 dwt. 21 gr. per ton (from gossan). 
Copper, trace. 
Sulphur, 25.4 per cent. 
