WITWATERSRAND

Manawatu Standard, Volume LIII, Issue 20, 20 December 1932, Page 8

WITWATERSRAND

THE FAULTED REEF,

REPORTED REDISCOVERY

Johannesburg, tlie great gold city of the world, is agog with excitement (writes Mr Arthur N. Nelson, M.A., in the Sydney Morning Herald). The people of this rich mining centre in the heart of South Africa have just heard that a scientist claims to have discovered the continuation of that wonderful reef which, since the original discovery in 1886, has yielded tire fabulous sum of £1,100,000,000 of gold. The reef which is at present being mined is approximately, one hundred miles in length, and the mining engineers estimate that there is yet a thousand million pounds worth of gold to be won from tlie rich strain already, known to exist- But Johannesburg, like Oliver Twist, has been asking for more. For years the people have been waiting for news of tire discovery of some continuation of the reef. THE PROBLEM. Everybody on the Witwatersrand has known —the children are taught at school —that the gold reef which runs for one hundred miles east and west from Springs to Randfontein is only the northern rim of a great basin of gold. But nobody has been able to say where the southern rim would be found or liow deep into the bowels of tlie earth the basin goes. The cause of all this mystery was the geological fault which occurs at Witpoortje, a few miles beyond Randfontein, the western limit of the mining area. At this fault the precious gold reef disappears abruptly. The geologists asked where it had gone. The mining engineers were equally at a loss to explain its disappearance. The strata had dropped—that much was certain. But how far? And which way? All the geological brains of the world could not have solved the problem, and mining engineers might go on sinking boreholes for the rest of tlreir natural lives without finding, that elusive gold reef. It certainly did not continue due westwards, as the known main reef ran. That has been the problem which has faced the mining industry for twenty years and more. And two years ago the problem remained unsolved. Johannesburg began perceptiblv to despair of reprieve from tire doom of gradual extinction held out to it as tlie inevitable consequence of the exhaustion of the mines.

But on October 22 it was announced that the continuation of the gold reef for 40 miles beyond the Witpoortjc Fault had been discovered. And, as I have said, Johannesburg is agog’ with excitement. The people are divided between hopes and fears —hopes that this is not yet another of the many false prophecies of the past, fears lest the scientists have been too optimistic.

AN INSPIRATION IN GEOPHYSICS

And this is how it all happened. It was more or less an accident, just like the original discovery of tlie main gold reef. One remembers that in 1886 two men, while walking to work across the open veld, bruised their toes against, and stumbled o>rr, pieces of rock, which, on examination, proved to be of tho purest go’d. And two years ago a young German scientist, Dr R. Krahmann, fresh from his studies at the Charlottenburg University, Berlin, came to the Gold City. In Berlin he had studied tho new science of geophysics; in Johannesburg there might be opportunities for practical application of this science. For a time lie made no headway. Then one day Dr Krahmann accompanied some newfound friends on a picnic to the Mulders Drift llill, a few miles north of Randfontein. They went there to watch a motor cycle hill climb contest, for Mulders Drift is a famous one. Dr Krahmann became bored after a time with watching the motor cyclists, and the scientific in him asserted itself. He turned to study the rock formations in the hillside. On this escarpment outcrop one or two of tlie strata which underdo the great gold reef. Dr Krahmann, out of curiosity, picked up one or two small pieces of rock. They were magnetite. They gave him the genn of a great idea. For two or three months he worked on that idea. He made secret experiments, and then, certain of success, he went to a friend who took him’ to one of the big mining houses of tlie city. And so the great search for the missing main gold reef started in earnest on the far West Rand. Dr Krahmann’s method was supremely simple. He had established that underneath the gold reef from Springs to Randfontein there ran a layer of magnetite. Now, he had a most delicate and sensitive instrument, composed of a series of little magnets, and which reacted to magnetite. Surely, he argued, if the magnetite stratum underlay the gold reef from Springs to Randfontein, the same magnetite stratum would underlie the main gold reef beyond tho Witpoorje Fault, wherever it was. And, assuredly, his little instrument would find that magnetite stratum. Ancl for eighteen months Dr Ivralimann searched for that magnetite layer westwards of Witpoortje. The magnets reacted, many calculations were made, and slowly tho engineers plotted out on the map the course the magnetite took.

FORTY MILES OF NEW REEF. And they got more and more excited. The gold reef, if it was above the magnetite layer, certainly did not continue due westwards from the Witpoortje fault. It turned southwards in a great curve. The prophecy about the great basin of gold was coming true. Here was the beginning of the western rim of that basin, running south towards the border of the Orange Free State. Prospecting continued on other lines, and Dr Krahmann’s findings were to a certain degree confirmed. Other mining houses were let into the secret, and, unobtrusively, options were taken up over the mineral rights of the farms stretching in a line from Witpoortje, past Banks Station on the main railway line to Capetown, past Welverdiend station, to the very banks of that tributary of the Vaal River, the Mooi River, near Potchofstroom. And a company is. now being formed to prove Dr Krahmann’s findings. There is little doubt that the gold reef is where lie says it is. Even the sceptics are convinced. But tbo great, the all-absorbing question is: how mnnv pennyweights of gold per ton of ore is contained in the forty miles of new reef? Until that is known, until the boreholes have reached the main reef and samples have been tested, there will be hopes and fears. It is a great gamble, but there is good reason to believe that Johannesburg is going to "become more golden than ever before. Visualise what will happen to Johannesburg if the gold values in the new reef are merely normal average values. In five years the population of the Witwatersraud will be doubled;

it will produce nearly £100,000,000 of gold a year. Visualise, too, tho possibilities of applying Dr Krahmann’s methods to discovering the southern and eastern rims of the great basin of gold. Already, I am told, Dr Krnhmann’s little instrument lias plotted the courso of the reef in tho far eastern portion of the Witwatersrand. There seems no obstacle to prevent that development. Already in the deepest mines the engineers have found that the gold reef llattens out as though the mines were getting near tho bottom of the basin. What untold wealth is there 1

But we are thinking ahead—perhaps a little too far. Much may happen to tlie world in fifty years. There may be no such tiling as a gold standard. It is a sobering reflection. But Johannesburg is agog with excitement.