HINTS TO GOLD PROSPECTORS IN NEW ZEALAND.

New Zealander, Volume 9, Issue 753, 2 July 1853, Page 3

HINTS TO GOLD PROSPECTORS IN NEW ZEALAND.

To the Editor of the New Zealander. Sir, —Sonic years residence in your colony, and a desire, from old associations, to see its advance decelerated, through commercial, industrial, and even political enterprise, induces me to offer you, for the acceptance of the public, a few practical suggestions touching upon the discovery of gold—a topic that/may yet be destined to fill an important place in your history—and one, the subject of which has, for nearly tour years commanded my almost undivided attention, and, moreover, whatever knowledge or experience I may have acquired has been at the expense of imicli hardship, difficulty, and labour ; neither has my field beeu limited— the stern outlines of the Sierra Nevada—the bold and mountainous districts of New South Wales, with the more chastenedglfeatures of th° Victoria Mines, have afforded ample data for the subject I have proposed in the present communication. ... > ! It does not appear to me that those magnificent results which have transformed the markets of your sister colonies from mere wool-sorting and tallow-packing transactions, into great commercial emporiums, widely ramified, and universally felt, have created with you that eager and wholesome haste for competition which one would have expected-in this golden epoch—this age of fortunemaking excitement; hut it does appear to me that so long as you can supply your mosquito fleet with blankets, and your ships with timber or potatoes, no well-directed efforts will be made to discover that magic mineral, which even now may be awaiting its advent in your streams and gulleys. Remember gold has been discovered, and that alone is a “ Great Fact” for New Zealand ! It is indeed true that your diggings hitherto have not realized either the wishes or the expectations of the community ; but it is likewise true that gold at Coromandel presupposes its existence elsewhere ; no experienced person, however, would have wasted his time in digging long in a locality where gold had been found of that character which 1 have been given to understand yours possesses •; because that metal is rarely found in situ in remunerating quantities, unless in the solid vein. * The words in situ may not altogether apply to Coromandel, but they indicate the proximity of the matrix to the place of de-posit,-and are not wholly incorrect. The matrix may long since have become disintegrated, and Sradually amalgamated with the-circumjacent deris, either in the form of siliceous clay, silt, or rabble. I throw out this hint, because I recollect seeing an Auckland paragraph, to the effect that certain works had been begun, or were in contemplation, for the finding of the parent vein, I tajee the mere fact of the discovery of Gold in New Zealand to be a most important desideratum —because it proves those creative agencies to be at work there, whether galvanic, electric, or otherwise, which have undoubtedly produced, both mechanically and chemically, the immense auriferous placers in other countries, therefore, other conditions being suitable, I think it very likely indeed that other fields than Coromandel may exist, both richer and more extensive. Is it not, then, desirable that the territory should he explored, and practically tested * I should think the inducements strong enough to warrant the outlay of either Government money, or private associated funds, in the formation, equipping, and sustaining of a properly organized party, well, and efficiently appointed—in order to which a Selection of men should he made, who are neither afraid to sink a hole or climb a hill, together with one or more persons possessing the necessary information of the physical characteristics peculiar to a gold country, and a practical knowledge of a thousand other seemingly trivial points, almost inexplicable, but highly essential, and well understood by persons conversant with gold-mining undertakings. I apprehend that such a party could, in six montns, or less, complete the desired object in both islands. At all events, this comparatively inexpensive project would satisfactorily set the matter at rest, or by its development at once transform the whole commercial and political relations of the country. It would be necessary for such a party to first direct its attention to the larger streams and rivers, of which you have no lack, and which are .alone the giant machines, formed by nature to collect her richest treasures, widely and sparsely scattered over the immense tracts of land which they drain ; and I will now proceed to offer a few remarks upon the character of the country most desirable to be tested. Where quartz predominates in the neigbbour- ‘ hood of large streams, the chances would be improved ; but its prevalence is by no means ah essential accompaniment; because, in most cases, , we must look many miles away from the points of deposit, for the veins or lodes which have contributed them—indeed, in rapid streams, with a corresponding descent, the larger portion of the disintegrated gold seldom reposes in the rocks adjacent to such veins. In the first instance, the heavier particles' 6r nuggets may, but the continued abrasion of the bed through a long succession of ages, tends to break up the most stubborn crystaline ledges, and thus precipitate the bulk of ’ the metal to a lower level, together with the denser bodies in combination. Thus, in stream prospecting , it will bc'apparent that, strictly speaking, a geological knowledge ,of the features of a gold region may he dispensed with, excepting in those cases where, either from a distinctness of conformation, or from other local causes, or the absensc of the necessary volume of water power, the gold may still occupy a position near the site of its formation. If, then, geological information he unnecessary in the kind of “prospecting” aboveinentioneu, the argument no longer applies when we treat of gully, mountain, or flat diggings; a small insight ' into their special features is indispensable, as 1 think will be proved by subsequent remarks. , There is a group of rocks, called Metamorphic or Transition, more favourable for gold and other metalic products than any other, and these rocks, almost universally hold the beds and veins of auriferous quartz. Metamorphic rocks 'are those ( changed during the Incandescent era of our planet, from an aqueous, sedimentary, or fossil- . tferous form, to their present one, differing only from the aqueous in being destitute of organic remains : they are gneifs (a kind of laminated granite, composed of quartz, feldspar, and mica) and several kinds of schists which it is not necessary for me to particularize ; suffice it to say that they mav be identified by their laminated texture and'their excessive cleavage, in short, their appearance is commonly slatey, and often rotten, clayey, or splintery, with a soapy, greasy feel during a certain stage of decomposition, and when chlorite is present. The colours ol the schists vary—argillaceous talcose combinations are a dull leaden white, whilst chlorite is green, and mica gives a black, dingy colour to the mass ; feldspar and hornblende more commonly affect the character of the gneiss, which is itself a kind of granite, elaborated into its present form through the degrading, igneous, and refrigerating influences of former periods, whilst the granite called Syenite is formed jby the of hornblende for mica. It is not necessary to pursue this part of my subject further. 1 have said enough to place before the eye of the explorer those peculiar characteristics so essential to a gold country : in fact

unless some or all of the rocks I have endeavoured to describe, appear in force in any particular section of country, I should look upon the ultimate chances of success, as being more than doubtful. In, upon, and over these transition rocks, then, the gold reposes. When in, it has either been formed throughout the volume of quartz, sometmies to a great depth, or, as a deposit, penetrated the fissures and cleavage lines—when upon , it Las, Irom its specific gravity, sunk through the superincumbent detritus, and lodged either in the vicinity of a hard slatey ledge, an impervious argilla ceous clay, or in the natural troughs and basins of the bed—-and when over, either the nature of the stratum is conglomiratic, hard, and concrete, or the presence of the mineral is comparatively recent, and its bulk incommensurate with its superficies in other words, fine, scaly, or porous. Ihere are two kinds of alluvial deposits—the one modern, and the other ancient or diluvial.— The modern deposits are those made by the natural phenomena of the Historic Period, such as floods, rains, rivers, lakes, frosts, &c. &c., and, consequently, consist of the surrounding materials —whilst the diluvial collections have a much more remote origin, and frequently are composed of hard flinty bracchia, or calcareous and ferruginous con - crete masses of quartz and similar rocks — (on this continent coeval, in many cases, with the older palajozaic). The white hills of Bendigo, nhd Makalumne hill in California, are the most periect instances of this kind that hav<i passed under my own eye; their constituent parts, singularly heterogeneous, are not always conformable to the organisms around, inasmuch as their deposition was at a period parallel with that of the tertiaries, and one far removed from the written ages of the world. In these formations, the gold usually rests upon the underlying stratum, be that Plutonic or metamorphic, and generally so deep as to preclude the possibility of mere exploring parties accomplishing any thing of a';decided character. It is then manliest that such should confine themselves to the comparatively shallow depths, and easy sinking of the more recently-lodged accumulations of the ravines and flats of the area marked for operations ; and to bear in mind that the nearer the site ofthe axisof disturbance is approached, thegreater becomes the probability of success. These axes may be recognised by the bearing and contortions of existing strata-—the protruding and upheaval of the Plutonic and sedimentary rocks, and the breakage or faults in the mountain chain—and have nothing whatever to do with existing or historic volcanic action. In prosecuting the search, it will likewise be important to ascertain the nature of the gravels and the soils, for if quartz predominate in scattered pebbles or boulders, and the soil be oxidised, red, or burnt-looking, with iron nodules or homogeneous quartz rubble, the chances are that gold exists in the vicinity, and that many of the hollows, and existing or old watercourses around, contain it, — their richness or poverty depending entirely upon local influences, or upon conditions, the agencies of which have long since disappeared, and of which no traces may remain for the eye of the casual or unpractised observer. When then a search for gold is undertaken upon the plans I have laid down, it will be useful frepuently to wash a sample of the surface earth, as, Ineed hardly state here, gold is so often found in this way, and sometimes in highly remunerating quantities—although, as a rule, surfacing is more profitable in the immediate neighbourhood of preexisting or partially existing quartz veins, which have for many ages, down to the present moment, been wasting away, through atmospheric and natural degradation. At other tires, (as at the Chinese diggingsnear Sonora, California) surface gold, embedded in a highly oxidized tenacious clay, owes its position to the action of those forces which contributed so extensively to the present physical structure of the earth, during alternating periods of submergence and elevation, and too remote for our practical elucidation. In continuation': —there are many mineral and metallic, or semi-metallic substances, greatly resemblim; gold, but only in external appearance, such as laminae of clay, slate, mica, and the pyrites of copper and iron ; and although these, or any one of them, might be easily mistaken for the precious metal by an unpractised operator, no one, once familiar with its virgin attributes, can be deceived —however, to prevent error in testing or examining a quartz vein, it will be well to be provided with a re-ogent, such as nitric acid, for instance, and likewise with a pair o {true apothecaries’ scales and troy weights, for ascertaining the specific gravity of a mineral. This latter method would be the most conclusive, and is very simple. I would further respectfully suggest that all districts be avoided, for the present, where the volcanic forces are either now, or have recently been in action ; because, as such areas generally assume an uneven and disordered appearance, the superincumbent masses consisting of lavas and ashes in every disposable form, from the hard and heavy scoriae to the light pumice and earthy or pulverulent tuff. It is by no means likely that the object in search of‘is, or ever will be, approachable —or, more probable still, that it ever existed in the vicinity—and in these remarks I wish to be understood as alluding strictly to present or historic convulsions. Again, where the granites and trapps (basalt, porphyry, clinkstone, &e.) appear in force, cither in physical combination or in proximity with the schists, or even in rare _ cases, the Silurian groups, and where the detritus and veins, lodes, or beds of quartz is observable, the best and surest results may be anticipated. The unstratified granites and trapps may be readily distinguished from the slates, gneiss, &c., which are all well stratified, and frequently much jointed and cleaved, and all bearing veins of quartz, more or less. Those immense portions of the upper crust of our Globe, the secondary rocks, which preponderate in the other hemisphere, have, I believe been ascertained by the Rev. Mr. Clarke, to be non-existent in this continent, but whether the opinions entertained by that most indefatigable geologist apply to New Zealand or not, I cannot, of coarse, say,'although such may be the inference drawn, from the close analogy generally ot the South Pacific groups —the coral islands excepted. However, he that as it may, I perfectly femember, ■when at Mercury Bay, tea years ago, breaking off a portion of prevailing rock there, which then struck me as being a rather singular specimen. I subsequently lost the piece, after keeping it three or four years, and I only know* now that it was a kind of indurated calcareous or cretaceous marl, but of what age, without a knowledge of its marine or otherjexuvise, I.cannot say; let others more gifted, solve these ahtruse laws which are based upon palaeontological research, and which alone can decide upon the properties and ages of such formations; suffice it to say, that should the cretaceous and calcareous groups exist in New Zealand, it would be useless to hazard a conjecture, on the subject of associate auriferous deposits; they are never, and likely can never be found together. In conclusion, as it was only my intention to convey a few hints on the subject of this communication, I do not know that it is necessary to extend them much further. I think I have written enough to show how and why an undertaking similar to that I have explained, should be carried out. -The interest that -would attach to it, is manifest; the results, in the event of success, w'ould he incalculable; its failure, as a pecuniary desideratum, would he trifling. As it would be necessary to obtain the sanction of the Maori Chiefs, previous to the opening up of mining districts, there might he difficulties thus thrown in the way, not encountered in those countries, at present supplying the world with the precious metals; but we must, on the other hand, concede to these persons a more than ordinary amount of natural intellect, and I think that that circumstance alone, in this case, would direct their movements in the right channel, and that hov»-

ever some the less acute and less civilized might demur, their action .would he neutralized, if not coerced, by the friendly advances or the miners, a class of men, not reckless of consequences, but obstinate in resistance, where the prize to be gained, might be a counterpoise to the trouble to be taken.—T am, Yours, &c. R. Cuoudace Joplin. 99, Hunter-street, Sydney, June 9, 1853.