GOLD MINING EXCITEMENT

Taranaki Daily News, Volume LIII, Issue 168, 25 October 1910, Page 2

GOLD MINING EXCITEMENT

BEST JIINE IN THE WORLD. By Cable.—Press Association. —Copyright! Perth, October 24. The Bullfinch mine is causing unprecedented excitement. It is generally agreed that it is the best mine in the world. The shaft is down <SO feet, and the lode, exposed to a width of 18 feet, is averaging 10 ounces. Another shaft is down 100 feet, and the lode of 10 feet is averaging 7 ounces. THE GOLDEN WEST. PROFESSOR DAVID'S VIEWS. ' Recently it was cabled from Perth—"The new Bullfinch goldfields have been inspected by the Government Geologist, who reports that they form the richest surface shown in Western Australia. There is evidence of unlimited potential mineral wealth over an enormous area.' Western Australia has been hoping to "strike it rich" for some time past, and, according to Professor David, there is every prospect that further gold-bearing belts will be met in the great west from time to time. The interest article following we take from the Sydney Morning Herald of the 29th ult.:— Professor David returned to Sydney on Wednesday ,from a lecturing tour in Western Australia, during which he visited the principal goldmining centres of the region. He said: "In the area of order crystalline rocks of Western Australia, extending from the Darling 1 Ranges eastwards to the edge of the Eucla artesian basin, there are at least four great gold belts.' This metalliferous series extends from the Phillips river, and Green Brushes fields, near the southwest coast, northerly to the Ashburton district. The chief belts from west to east are the Southern Cross, Coolgardie, Kalgurli, Boulder and Hampden Plains ' belts. The West Australian Government Geologist has come to the conclusion that in this vast crystalline area of rocks it is chiefly the soda-bearing granites that are especially favorable to the occurrence of the economic minerals. This I view is also held by the Western AustraI lian Mineralogist. A dark greenish black rock known as quartz dolorite is also favorable. This rock is developed on a large scale in the Kalgurli and Boulder areas, and has there been subject to a vast amount of pressure and crushing through irresistible forces resulting from "fracture of the earth's crust. "The great gold deposits of Kalgurlie are chiefly developed in either the | crushed quartz dolorite or in the strata | which immediately adjoins it. Wherever these gold-bearing belts occur evidence of a considerable amount of fracturing and faulting can be seen. The gold deposits, however, are not always bound.ed by sharp walls of barren country rock, as is the case in most of our goldfields. It is not possible at Kalgurli and Boulder to tell, except by assaying, which rock is payable and which is not. To the eye the bulk of the rock treated for gold does not appear to have any mineral value. In appearance it is a light to dark-grey or greenish-grey slate rock, and is charged with very' finely divided sulphides and minute quantities of telluride. "Some of the shoots have been proved to be gold-bearing for a width of fully oflft, and for a length measured horizontally of over three-quarters of a mile. They have been proved to pitch downwards, and to be still carrying gold at a depth of over 2000 ft below the surface. "In addition to the evidence of one or more fault planes near the centre of the gold-bearing zone there are also numbers of small cross veins, known as gash veins, which are at right angles to the general trend of the belt. They obviously have been produced by the dragging effect of the horizontal' movement of one wall of the fault either leading to or opening out of the rock thus strained with these small transverse cracks. Gold-bearing quartz is almost invariably present in those gash veins, and occasionally different tellurides of gold, silver, mercury, lead ,etc., 'in fair-sized lumps are found distributed throughout the mass of the ore body. The cost of treatment of most of the stone has now, by means of improved metallurgical processes, up-to-date machinery, and skilled management, been lowered to about £1 per ton. The field nas already produced about £92,000,000 | worth of gold. It is claimed that the mines have paid about £40.00.0,000 in dividends. There are two features which promise considerable permanence to mining in this region. The first is the very gradual passage of the highgrade with the low-grade ore, which involves the abandoning for the time beof large masses of low-grade ore. which no doubt will form a great reserve for future working when the cost of working and treatment has been still further reduced. Secondly, some of the ore deposits, such as that of Ora Banda, about 40 miles north-west of Kalgurli, make such very inconspicuous outcrops that it was only a mere chance that they were ever discovered at all. "In fact, the country in which" this last-mentioned ore deposit is situated appears to be just a very ordinary and typical piece of scrubby redsoil country, ot which there are many thousands of square miles in this region. There is every prospect, therefore, that other gold-bearing belts will be met with in this area, from time to time. As <in example of this may be mentioned the recent new find of gold near the Southern Cross .field, which is said to be very encouraging. It is obvious that tho expenditure of £3,000,000 by the AAVtern Australian Government on the CooJoar-die-Ivalgoorlie water supply scheme "has been amply justified. By this scheme a liberal supply of water has been carried inland from -the westdrjr face of the Darling Ranges, from tlte Mundarin«

Weir, on the Helena *iver£ for at least ? miles to the east. This water is, of course, used for the mining machinery .and ore. Regarding the soda-hearimr granites, it has been observed by the geological survey that whenever these particular varieties of rock are traversed by the coarsely-crystallised light-colored dykes known as pegmatites these dvke rocks frequently contain limestone, wolfram, stibio tan ta lite, and manga no tantalite besides other minerals. The metal tantalum is got from the metal maiigano tanta.lite. At AVogma, in the • lilbana district, this tantalite has been : ouud associated with 'monazite; a new ' radio-active mineral known as pilbarrite has_ been recently discovered in the .-ame rnfn,° o n i ff a decp . ■ vello ' v to orance--01 ed substance, which contains over ?0 i I per cent, of uranium,"