GEOLOGICAL SURVEY.

New Zealand Times, Volume XXIX, Issue 6400, 24 December 1907, Page 6

GEOLOGICAL SURVEY.

THE HAURAKI DISTRICT. BULLETIN No. 4. Tho report on the _ geology of the Coromandel Subdivision, Hauraki, Auckland, just issued comprises Bulletin No. 4 of the new series published .since Dr Hell assumed the directorship of the Geological Survey. Like the previous bulletins of the series, its c'-nnibiDon has been carried out with extreme care, and should prove of incalculable benefit to mining interests, in the compilation excellent work has bor*n done by Messrs Colin Fraser and James Henry Adams. The Hnuraki division constitutes at the preent time the most important goldmining area in New Zealand. In its southern portion is located the Waihi mine, which now ranks among tho world’s greatest # gold-producers, while further north lie the mining centres of Thames and Coromandel, bath famous for the great bonanzas of their auriferous quartz veins. The area from a geological point of view, says the report, is a wonderfully interesting one, presenting on a grand scale all the evidences of vulcanism and attendant solfatarism of former geological times. A Tertiary volcanic complex, referable to several periods of eruptive activity, overlies folded and denuded sed’mentnry formations. The extrusion of the volcanic materials, which form masses of considerable thickness and areal extent, has been intimately connected with erogenic movements. The consideration oS its structure, petrology, and ore-deposits, shows that tho Hauraki area presents many striking resemblances to the Washoe, Cripple Creek, and Tonopah raining districts of the United States of America, and to tho ancient mining field of tho -Hungarian province of Transylvania of Europe. The study of the Hauraki veins and their surroundings may be expected to throw additional light on the important and fascinating problems connected with ore-genesis. The coast-line, which a total length of some 190 miles, was surveyed in detail. Tho main streams, together with many of their tributaries, were carefully traversed, and, in addition to an inspection of the various rock-outcrops encountered therein, a careful examination of the stream debris Mis carried out, for the purpose of delineating tho areas in which auriferous veins may reasonably be expected to occur.

Tim earliest European settlements on the Cape Colville peninsula depended for their existence upon kauri timber industry* The township of Coromandel is named after a British man-of-war which, in 1820, put into the harbour for the purpose of obtaining spars (kauri) for the navy. Some considerable time after this date the low grounds of the valley became the scene of active sawmilling operations, and thus a European settlement came into existence. Ring’s discovery in 1802 of fragments of highly auriferous quartz and detrital gold in a crcek-bed throw quite a new light on tho future prospects of tho district. There was an immediate influx of a class of pioneers very different from the bushmen—namely, the gold-diggers and those who invariably follow in their wake. .Even at that early date the possibilities of Coromandel as a goldfield were hopefully discussed, and subs quent discoveries were sufficient to establish it as a permanent mining centre.

The discovery of gold in Australia in 1851 by Hargreaves had to some extent a beneficial effect on New Zealand, in that it directed attention to the possible occurrence of gold in this colony. Prospecting in New Zealand was, therefore, commenced, and received an incentive owing to the formation in Auckland, in October, 1852, of a Reward which offered a £SOO bonus to the discoverer of a payable goldfield in the northern province. Within a week the bonus was claimed by Mr Charles Ring, then a sawmilier in the Coromandel Valley, and, prior to arriving in New Zealand, a gold-prospector in California. King announced that ho had discovered a payable goldfield at Coromandel, and produced at the same time specimens of auriferous quartz and a certain amount of fin© detrital gold, which he had obtained from the bod of the Whangarahi orcok, near the hose of Tokatea Hill. Thus is recorded, in October, 1852, the first authenticated gold discovery in New Zealand.

Forthwith negotiations were opened with the Maori landowners to msrmit of goidmining on the Hauraki Peninsula, and resulted in an agreement (dated the 30th November, 1852) that the area lying between Cape Colville and Kauaeranga (now Shortland, Thames) should be opened for mining for a term of three years. Under this agreement the Government pledged itself to pay per annum to the Maoris—for less than 500 men digging, £600; for 500 to 1000 men digging, £900; "for 1000 to 1500 men dgging, £1200; for 1500 to 2000 men digging, £1500; and, in addition, 2s for each miner’s license issued. To , meet this and other expenses a tax of £1 10s per month per. man was im- 1 posed on the miners, with, however, exemption for the first two months. * Within one month from the date of this agreement, three thousand men wore on the Coromandel field, and the hitherto quiet sawmilling settlement at once assumed all the characteristics of a newly-established mining camp. Tt was discovered, however, oven at that early stage of mining operations, that the auriferous, areas were not continuous throughout the field, and two separate camps wore established. The results in each case were very disappointing, and of the three thousand miners who rushed” the field, it is said that only fifty took out licenses at the expirat'on of their two months’ exemption period, and even these could not afford to pay the heavy monthly tax. Failure to locate payable gold, combined with the unfriendly attitude of the natives, caused a general exodus of tho diggers, and within six months the whole enterprise died out. The subsequent development of goldmining at Coromandel is matter of history. It is estimated that the goldproduction of that d strict up to December 3Lst, 1906. was £1,743,790. The report states that Coromandel will long be classed among the goldfields which afford ample scope rather for the speculator, who is prepared to take risks in the hop© of reaping largo profits, than for tho investor who expects a regular percentage of profit on capital employed. The field can hope for little from improved metallurgical processes, since it possess s no workable low-grade orebodies. In view’, however, of the heavy expense ’at present connected with pumping, winding, and underground exploration, every device calculated to lower the cost of motive power or to cheapen -in any other way the existing .methods of mining nr - ***- Ha counted a decided advantage.