THE AURIFEROUS DRIFTS OF OTAGO.

Otago Daily Times, Issue 11307, 28 December 1898, Page 2

THE AURIFEROUS DRIFTS OF OTAGO.

(Fnoii Ocr SrEWAL Correspondent.)

INTRODUCTORY. The remark is often heard that the practical assistance mining is supposed to have received from geological investigations and is much over-estimated, and that rather is science indebted to mining for" "numerous disclosures of most valu-. able .information,. 'Vfath regard to alluvial mining there is a strong show in favour: of the, argument; but in saying so much it must^ be borne in mind that geology's realm confines itself' to locks "in situ," which constitute the so-called Solid crust of the earth; When the material overlying; and no doubt derived from these rocks, comes to be dealt with, geology speaks with less authority and in more guarded terms,; leaving to physical geography the solution of many of the "problems that, present themaelvfes. However, in both sciences a great deal has been done to help, on the practical work, of .mining, and if they have not met1 every expectation and desire of-the ■ miner the fault lies mostly with the expectation. It id clear that the changes of what may be1 called the skin of the.earth harf 'parsed through 4 are much more varied in theii' causes as: well as in their effects than ,the changes! that have' formed and then broken up and altered the solid crust '.^__' of our, globe. Yet a. great deal has been ?., done by- the collection of reliable .data to ::. place -the miner upon the Tightl track. So" far ■ as-'Otago is concerned, the most important effort in this line is the "Beport1 :•: • on the Older Auriferous Drifts of Central ,i. Otago," by Alexander M'Kay, F.G.S., Go; "vernmerifc geologist, published in handy. "''■'. form',at 2s 6d. The report should be, in /the hands of all New Zealand miners, and i ") studied by them with close- atention. ■ Every locality where mining is" carried on is'mentioned, and'its peculiarities ■ are .-,-. ,<touched upon, so that no one can fail'to/ • / derive a certain amount of benefit from its j'v\ study. The report is written in plain ;;.,/'language, avoiding vas much as possible !/v 'scientific terms and technicalities. /Whatever value: the quartz lodes ' of. . Otago may attain to in the; near future, : when/the •manner of their occurrence is' better understood; there; is nib gainsaying; |r the Vfact that up to the1 present mining; / in Otago has been, and is likely to be far an-indefinite time to cdine, principally con- •■'■.'.■ cerned wifli'alluvial deposits. By far the, /';■/. greater, bulk of the output from the gold- :;■' : fiejds of Otago. is derived from the auri- ■■".•.. feroiis drifts that clothe the hillsides .in. . ■ terrace formations that fill ancient lake and //..-/ river beds, or that rise in dune-like hills /■; and; elevations. It follows, therefore, that ;fr ,any,'information shedding light upon the' t*/; i occurrence ' "of these auriferous * de- |/:>: :posj[ts/ ', ia\ ]oi the greatest import >//■;/';/to; fi/^he-. colony, Mr M'Kay's re-/, jy'; ipbrti is' coinpijed with the object of ;, ; supplying., this information, and furnishes ■■<■' ■■■> :it-in a most comprehensive and useful form, ~ ■ / so-.-'that .all- who' rmr- may read. ■' Nor is |,;;/ /the report1 only complete and of 'the ':"'■ •■. greatest .^practical use alike', to 'the work- ■'/;;■ ing-miner, the prospector, a.nd, the investor,'. :"■:/• but'iff is also well timed. : ■■'■■''X ' MINING APPLIANCES AND -METHODS !;/ ;have.now reached so advanced'a state of '■:,; '■; ■■:■ .perfection, and variety as, to., be; able -to [^C /cope -with almost every obstacle surround;.. ■i-:-: ing,-thei actual pursuit' of gold getting. : iit ItK.! particular places under -peculiar difficulties/ ig;,* ;In Oago the invention and improvement 5;';;, of mechanical devices have far outstripped ;|, : alj^h^: available knowledge about the- aTtri/ ''}'] * fgyoijsr (deposits. the machinery and ■ methods • {'■jare.so'eminently calculated to-turn to ftc* 15; cbunti/; The report how under considerai'-' v tipn will help to remedy this defect in'; a-measurS commensurate with-the use that r of 'it.,..'.ltvdraws attention' to the' that jip.'to 'the, ~i"4; -''-;ptt8etiir.%e' entirely; uiiprbspected,, ,pr that ;K;" /Tiave beeiji wrongly or imperfectly,,attacked, I-)''-'*- ;'-itnd furnishes a fund of information that' //!/• cannot Ml to hear fruit.\ ,'•.-. >. -~■.-.■ > /■';/ ' "'■ Development and . extension of mining. |-■"::., '.(Jepends hbw-1 more upon correct'"' kriow;-' ;f?/ -ledge- of the -manner of: occurrence of the; .''i^-'v *gold''%Hto''-upotl'"tHe' means of! winning'it'. * Ifeftv/Such remarks as: "Yes, the gold, is tßere; Sa;ij:,:but it /doesn't- pay!" are'becoming rarer, 10'y every/day. • Provided the gold be .there, |:{?;J- ■wsya.arid'm^anr-win be found itp rifake. it. fi,- ■■':'PWJ.'What/Is.warited is a mbfe generally" jp;: .>diffused knowledge of where the gold may ii" / be- found with the" greatest -degree of.cerX f//tainfcy: In this connection it is. to be're-' I :fi S : gretted;tKat inithei, local museums a, more ■Wifi^i.'isygt^matie-.fttteinp^fc has not; been -made to |li;'v» preS&mV' in fully indexed sample-tubes the ?yi-^/]fiahner;-of;oc(mrrßncei' Jof the'-principal ebld-^ I£;';/ bearing "drifts of^Otago. Much has Jbeeiv= §SjV! '•■; done in the collebtiori of samples of sand |p;W;and /'-stones /scientifically1 arranged: IjljKi/affit/ /lajjelled, which .no, doubt 'are !s&i upiry:\; the^.;■'-. greatest'" value .to .men, of i^rt^^oiJßntiflio 'attainments; but'what is more. p,-gfigaitlr .required; is, to use a homely 'fe '7 phrase,:: a speaking; likeness of. things as i|/^^tiey;,', are, . showing to -the mind of any, fe/'":irit,elKgent and observing individual at a iM:p>!^glance, how- miriferoual wash is or. may be; 1^;; met) With ; over 'or. under the prevailingg|.i:','false "i bottoms; which are recognised by ftJj .-'geojogy, a^ relating to epochs when 'the is Supposed to .have been distributed. &■■>■: ■E^dtnce presented In such a manner,would i|rf;<.t.«erve all the purposes of 'illustration fax Sfef?- /hettei '/than, any diagrams. or verbal de|S¥j!scripJion>;, ,: /:'; ,;.,', /■ ~' ;.. ■ : ;." fS^^t■':W¥?n ( .in the early sixiiies the Australian "invaded Otago, they, coming with" jj||!tyiliißjr/nbjiions .of,-. ...:/■.-■! ■ ■•,'-•■'■'■ ■ :|p^;]MOT;LEADS AND,ELABCBATE MININa PLANT,'; l^i?; (Were-inclined to'form a rather p6or idea of. ||>;;|t^e! permanence of New Zealand gold mini|;{} ing;rjiuhping to'the conclusion that in a ||iy';fety,yyears/the whole Middle Island at'leasf Jl^Vw.oiild ihe /cleaned, up, all the auriferous gjQfwJ^h' sluiced >intb: the Pacific Ocean, and te4: ;dtK^fi 'W a quarter, of a'century at the ut#s/mi)st ; no more would,be heard -or known *J"//of^gpld:! mining -in Ithe land: , Yet here we j^^MCfli ::-after ■-' flfearly forty yeij,rsr c*f" mining,; iHt}"eiporting. for'ithaf period gold, at an; ave|/;;^/;rage;ff\£l;pOOj(WO;jwprth! ) per anmim^just, p f^.»b^ti;reMy:to;,make,a:start in real earnest;/ ;;g:^:AWe/ftre/ now /perfecting an entirely neW S2|;:;. f>i ' go'lcUgetting, and are beginning |i;g /;t^;!pefqeiye; tha(> we have deposits of aur'i-J-Jii/te^ous/drifts .which in extent and conse1-' rife- 'quently permanence make up what they ivy-;.'.. i inay'-;,'j5.e..'-lacking in richneas^ as' cpmparecl Kv'Clwith 'the deep leads of Victoria and New pt::;;^6uth'^ale3. '■■ ■-,/,. ■ ~,'■-■. ffi /It IS an oldy and trite observation that a...f51 cotaparisbris are odious, yet they have %/ their 'uses, and are not likely to go out ;;;;\^of,:fasKio,nv Comparing, then, Otago with //■/Victoria, which beyond all- question was 'i&'.'./'thS1' 'richest goldfields district the world. V:, has-kriowh, we find'that in respect of per■'.mpnence; of auriferous wealth Otago domes /; off ail easy first; In fact, no known gold-' v / / field has ever experienced a revival such /-( asl S; now infusing a new life, into gold--1 . getting pursuits,in, Otago, /So pronounced ;;' has this .revival_been already, and..so full, '*:■■■■ of.'prpmise is it,' that it would be" nothing -' short' of' taking, an unfair advantage by / / pushing the comparison- to the full horizon, I'-,"-',:' however legitimate.the process.might, be. ';./.. /Roughly viewedi gold-mining activity is ',''; . limited to known leads and lodes in -Victo- .." ri :^,, already traced to depths from the surf .' face, seriously affecting their economic :'.': . value, while the chances of the discovery 1 '; of :new,,fields;.are, exceedingly:i.remo'te,, In ;/ . Otago/ we "have only just, tapped our deep ■:■':: ; leads thftt exist above the surface, and /it - can scarcelyibe said that we have bgguri -// to dive below it. However, we know that: I* /gold does liev in layers and beds to great J: /depths,;.and. if.the metal is not arranged g?O in leads confined to definite courses, as in '&'• Victbria.^the .distributioh is more general. $;-.. OLthel richness of the deep ground in Otago "..' ' -little is known. The best key to the pro- ; ■ • blem ;is the. ground that' has been 'worked. I, There, is no reason for doubting that gold' I bearing .drifts below the water lev,el p£ I the , cotmtry are as rich in gold as those I 'above it. If they are as rich they will L d 0.:.:, '■/.- mi' Next to the question of the richness of p the deep ground in Otago is that of the 1,//maniler-oi occurrence of the gold. That I? /once;definitely ascertained^ it will not be., f v^.. long-before the hidden; wealth will be fv ' -brought to light. ' The readiest means to ■? ' vproSpect;'deep ground is ' ~ ■"■■.■,:■/'- THE BOBING BOD. / It is a common mistake to suppose that sV the boring rod will discovei the gold in > weighable-quantities, and so establish the ■:'■■■'■" saact value of the ground tested. All/that ; T-^; can be expected of boring operations with '-';'■•-," any degree of reliability is the depth of the /' ground,- the angle of dip of layers of /. gravel, the order-of succession in which /they overlie one another, the relative thick-

ness of the different beds, and above all the character and nature of the material composing the- beds. From these data must be deduced the_ auriferous,.value if the deposit and the manner pf attack likely to yield the best results. Were a party undertaking boring operations* to depend only up.on the actual getting of the gold in specs and nuggets they, might bore for a blue mqon, and in the end fail to obtain a prospect, and yet the same ground may be rich in gold." The reason of this is very obvious. Gold is never- found evenly distributed, and in the best, and richest leads there are numerous blanks totally devoid of gold. /Now, "a boring .rod, or even the diamond drill, covers a disc of only a few inches in diameter, and so may easily miss the' gold if present. On' the dther "hand the drill may bring up a rich patch by chance, which, taken as a sample of the average value of the ground,' would be 1 utterly misleading. , ' ' All this being so, it; follows that boring, to be of practical and reliable use, must be conducted by men haying' a perfect knowledge of the drift' deposits of Otago— in ; fact, they iriust' be "expert; geologists.1' The results of the borings 'should be permanently and' exhatistWely rfeedtded; so M to serve as reference for all time\ -! .-, The Geological department "6f the cdlon'y should be induced to conduct boring testsin the ihbst likely places of' the colony, making the results known* in the same fliaitiner. as Is/done how with .geological surveys. The 'department might, also assist private enterprise in- this, direction by giving opinions Upon the material Obtained from bore holes submitted for scientific investir' gatipn, and.dispense siich advice thereupon as would aid in the successful prosecution: ofJthe1 work." *' ' ■"''.■''.' ' " The issue at stalce fs such that suggestions like the aboveT: should' at least receive careful eonsideratioil from the Mines department^ and if possible be carried but without further delay. "The present state of knowledge' relating to the auriferous drifts of the Middle Island is ,;6f a natUre to. make interested parties lotig for more light on the subject. Just tipto, when.'a wave, of prosperity is ani?natii|g the mining mind with a flush of "enterprise, would' be the time to launch but in the direction indicated. ' - ' ; ■' ■ ■ Whatever the opinion that mayvbe held amongst- practical men '.and' mining investors as to the value of our auriferous drifts, it is certain that their' enormous extent fully justifies.a very.,careful examination of their economic worth,; '.which is determined, by^the promise of .their auriferous character, arid by^the manner" oi "6p.enihg/ and workitig1 them. "On,both these'all-im-^ pdrtaht points the boririg^/ybd—'or, better still,'the diamond; drill-^c^n; giye,'the, most satisfactory inforinatibri'"at' a cpinparatively ■ low, cost. To do ttis, hftwevef/'wie' boring operations., must be cpndiicted under thoroughly competent supervision.