Show I SPURRS r R REPORT G L 1 eminent Government Geologist st Presents Presenta Sonic Some Pacts Facts 11 1 About Aboul New District VISITED CAMP IH IN LAST MONTH I i 1 At Goldfield Auriferous Deposits Oc Occur Occur Occur cur In lu and Other Geological Conditions The new hew ClinT camp of In 11 L Ne Nevada Nes s vada vala was wa In I of oft t this tM year by hi Mr J 1 V M purr of the United tAte State oal survey This I south of district lies II about fl H miles in the lite rono and was WU U located late pIng erring of 1901 Shortly after the Die dis discovery 11 I IC C covery covel ot of gold fOIll goi In this district It was wu visited vl by Mr Ir purr A Wile littLe work was wu J then In lu on what l i III now known an Columbia mountain but buL up III to that j time no flO rood good Had 1 been snide made madem In m January and February 1901 1101 how i ever vor er rich find IndA were wert made In certain cartaIn i The Tilt t trait roll of ot Columbia mountain f district dl hu hai now HOW an approximate lallon of or The town tow II of I hll sprung up Ul and iv n number of small smaller tab tabi er el adjacent camps amps have ha been lit i J It 11 Is le l estimated that up to the tho thor f time ut worth of r district ore has hM beon been from tho the Most Malt of th shipment have hive been I made In Iii the last lut months month I I The dIstrict Is bounded on the WeltI Wilt west I J In m part by a ala lava I capped mesa luau m Iho thu thuI I 1 it of which haw has laid bare the un underlying rock The rhe aunt auriferous 4 erous region U Ii I characterised by numer numerous ous ou low la irregular Irre ridges standing out outI I 1 from the lower and morn mono nearly level These ridges owe their origin to hard reefs reefe of quartz quarts which form torm their crests Their resistance to ero erosion sion clott has ha left loft them protruding thus hue above tho the general elevation elev lion and In these thellO quarts quat roofs the auriferous de di deposits d posits are Ille Columbia mountain Is Ia s the most mOlt prom promInent promInent blent of these thON ridges and amI ome notel on Its Ita geology were mode public by Mr Spurr last hut year In bulletin 23 published by the United States Iut tate geo go geological logical survey Near Nar the tho Mouth end Ind of or orthe the ridge the rock II Is largely an fin Igneous Igne Jull rock consisting of qUirt quartz and feldmar which Is In sometimes of structure and very oven resembling quart Cuart rite KIte White or Is II a sometimes p ont and pure quartz qu veins or dIka of similar aIu I y occur TheRe Theno rocks are Art f 1 Ie Into a lark dark siliceous rook rock Jan jas JalI I h Is II probably the result of ot tho of ot an original lime limestone tone stone Onn On suspect that this thu limestone tone wile una and amI and that the In 18 i LuG also of ot geological age On the th north end of the moun mountain thin tain the rock Is La a II i very vary ory much altered rhyolite In 11 this title rhyolite are Ue brood 1 masses of ot white to purplish and red reddish redo o dish shorty quartz which extend Ir II Irregularly Irn n regularly In n II northerly nl direction This Thia quartz is L simply n a highly rhyolite The Tho arms areas have hRu Ill 11 de ned wills and the highly lied Ired portions portfolio which they tho enclose are very err I IN I AREA On Ida his last laet visit Mr took notes notee over an nn extended area orea and made In Interesting Interesting additions to his hIM knowledge ot of the geology of the tho district dl The area anon of known oro ore bodies b has haa spread since loot year ear 10 no far tar beyond Columbia mountain that values art ar now no found over an nn area orea about six aix miles square qu The Tho most mont productive area rea measures two to two to and nm am miles In III either direction The fhe chief mines at It the pres prea present ent tnt limo tho the Jumbo tho the Combination tion tho the January and the Florence all grouped together about a mile south of ot the end and of Columbia mountain Some nine nino miles southeast of ot Columbia mountain ml Is III tho the groups group gro p Including the Vernal the th Quart site IlIe and Black Butte Dutte from which ship shipments ments have havo also been made mud Other ore deposits havo have been developed In various arioul parts parta of the field HOCKS OI OP VOLCANIC ORIGIN Tho rho rocks In that part of the field visited by Sir Nr Spurn Spurr on his bl lit last trip the region of Columbia mountain lla ILi and the tho Jumbo group TOU of mines we found to t bo bl almost entirely volcanic consisting of lites tufts tuns and ba ha units unIte all nih probably of or age The and of ut Columbia mountain are arc hardly hamly represented In the district although at the Tonopah Tono h Club mine mIM R II patch rth of lime Ime limestone stone atone In III this eRas caw constituting the or ore was wag seen n The predominant socks rocks are abundant and antl while basalt Is Ia taro rare One examined microscopically from near the Club Is n a hornblende Ding the early andesite at Tonopah a patch of or basalt from n nar ar the Florence 1 Is an basalt like the basalt of SIebert mountain at Tonopah The resembles re the of the Gold Mountain district which lies Ilea about four miles south lOuth of Tonopah on all the road between Tonopah and und an this thin Gold Mountain rhyolite again resembles olot closet rome come of the th phases of the earlier at nt Tone Tono lh pah The relative age R of the rocks reeks at G has not been determined but butU It U probably corresponds to that hit of simi lar Ian rocks at nt Tonopah S AND S SAt At the ores orel occur In both and aM andesite showing that occurred subsequent to the eruption of both lives lavas At Gold Mountain the tho th deposition of the ores one evi evl evidently dently followed the ho eruption of the lb and at ot Tonopah the eruption of ef the earlier was Wall succeeded by a period of which produced Irregular veins that frequently carry a R larger proportion of or sold gold than the locally more Important veins formed after the eruption of the andesite There Thee U Is therefore the h that the deposits are Aro identical In origin with the later hater series Cerlia 11 of veins elna at CIt Tonopah indeed there are at in one plat plan at least flUt mineralized quartz reefs reefa in rhyolite rhyolite rhyolite lite tufTs tuffs that have hae the same lime characteristics AS Aa the tufts tuffs of the Geld fIeld reefs Bond and assays of these Tonopah Tono Pith pah ah deposits as aa known to Mr Spurr purr two years rears ago alO have hae shown a moderate amount of nf 0 gold JOld and nd silver silverNO silverNO NO DEFINITE At Goldfield there are no definite veins vein The outcrops of the quartz bod hod bo l s are Irregular straggling branching 4 anti nJ apt to disappear suddenly Neither i were any allY definite systems I leml observed I f t I pt lV t p r i tt 1 I II t I hi r though further study might reveal them There seems eema lee 1011 however to be a 1 tendency to elongation In III a direction The outcrops may my even b be nearly circular or slut ana fri fr they the are ure roughly and Intermittent The Th quartz Itself Is I grap rap and Jasper It le is almost entirely due to tl the of the she v canle rock rork In I It occurs occur no ary cry vein quartz was ob obI observed I served WORK OP OJ HOT IlOT SPitiNG All Indications show that this Billet Uon and nd the l nying miner II U the work of ot hot and that the irre irregular ular reefs W re resent sent nt the Lb horizontal sections section ot of columns of at rocks rock traver d by rising columns column OJ 01 hot water Had toe the W rocks been strong l I ly fractured we have had Id veins like lii those tho of the early at Tono Tonopah peb pah which were also allO Probably due to hot hint spring action but at the lads of ot such a fracture system resulted In lit I this curious and rather unusual type of ot deposit It H follows that the quartz quarts reel reefs will probably M II a rule extend deeper vertically than horizontally and ana anaM nd M q have roughly the nature of columns or py rU time the greater rester lart rt of or one of these thele Jut quartz reefs reel contains or orno orno orno no gold Microscopic has hILI shown In one ease case AI that In such uh quartz quarts the lIIl iron of the Is I a probably main mainly mainI ly hy Is II I that the iron Irn sulphide I has haa h been ben formed by the notion action of sulphur contained In the tho hot spring waters e upon the tb Iron silicates contain contained ed oil In the hornblende and blete This rids explains the th absence of oC gold ns as the has hii the same ale origin as U a the bar barren br barr r ren fi pyrite pyrie near the ore bodies In the country rn rock reck at Tonopah WithIn some of or these hew th I barren reefs of oC BUell rock rk at a however prospectors prospector have sometimes discovered portions contain ln lag gold Men el In large quantities Such portions are ar usually or Irregular like Ik the main quartz reefs ret and they are era not easily lly from the barren rn quartz except by pan Ilan panning Him ning or assaying but It teems seems Hell probable that these th shoots are the rest real rel ore or depoi depo Its It and md nl that the mass mall of the reefs rf constitutes merely a jacket or casing cling ezieb ac is I Is shown Inn to surround ore or bodice IN In some other parts pat of tho iho world While this thu siliceous easing casing may mRY maybe maybe be b 26 25 2 or 30 3 feet leel wide the nor Ilor or lion may be b only I 1 or 2 3 feet and the form and extent of 01 this portion porton l cam evident ellent only after ater the ore are has bits been ox x I la is then seen en to have ha VI a a definite lIke shape often oten more regular than that of ot the tue whole outcropping ret reef though It baa haa ha usually a I limited extent In II the direction of ot Its I greatest elonga elongation lion tion lon It I seems acorns ems probable that these thee pay py shoot represent the th main channel of ot hot water circulation while the casings are aro the result of the soaking eking through tho the adjacent rock rok The ores r are often of or vey high grade gre As an extreme example may my be b noted a ft shipment nt of 01 1 14 tons from the Sand Sandstorm Sald Sandstorm storm Kendall endal claim which when worked orkell In n a 1 stamp mill yielded net while the tailings still contained about abut 1000 10 to the tho ro ton From I rom the lie tl Me Mc lease on the Jumbo MO 0 O 0 was wan a taken out In five months month from flom froma floma a snare apace s e of ot ID feet tet horizontally and Ind 10 feet vertically on this the th sheet One small ma shipment of or 81 pounds iund of ot ore or from fron this thin lent loz gw gross groat r returns return of or The whole hole 1 of ot the camp his has hAi been from we are r which may mv be b roughly estimated as al averaging 1200 0 to per Jr ton or more coors The values value are AI all In Ingold II ingold gold silver lver IH in l usually ab absent absent sent although the shipping ore orp from the mine mint contains contain from 1 to 3 I It I Is 18 Important to oll the origin of at this rich ore or In II order to make mako pro pm prophecies for tor the th future Most MOlt of 01 that tat which up to the time has ha bo boon bean n extracted ex t ra to lies hos been beau bon oxidized oxidize ore oro The Tb Theor I or ore 01 ire era mixed sulphides sulphide usually RII oxides clear olear up lp to tho the surface Tho The oxidized which follow foto cracks nod and Rn seams lU rl is I usually several timen sometimes several veral hundred times Ure as n rich as RI the por portion portion tion lon The Irregular spongy nature of the free frN gold gO particles In hI im erh n h oxidized o material completes complete the he pr f that limit this I gold Kold has ha been ben dissolved llod and r In a I concentrated form torm during durn this the pro process cess cells of oxidisation Iron sulphate de derived rived front from oxidization of the te pyrites Is s the probable agent A peculiar yel low costing coating pointed out Olt to Mr Spurr as ni the best beat bt sign of values valises In the oxidised ox oxidised I ores or wa WM shown hown by Dr to be he R a basic sulphate containing both sodium and potassium f other Oilier sulphate sulphates Inch au an alum and gypsum These Thel oxidized ores ore orel ore are prepared for tor shipment by screening the th floes fines being shipped and the coarse COIe quartz rejected VATER Il E mOi Aa As Al the tho water level at nt Is usually high for Cor this desert country water lter having been encountered In Inse sev several oral eral erl shafts at from to JOO 0 feet rett it itIs I itIs Is II plain that this oxidized ore li is only a n temporary supply In n the Combination and the Florence Forence how however hoer ever sulphide ores oros of very verr veI high bight grade have hae been n found below the oxidized oxidised sone zosie In these thel mines minesa a dark gray fray mineral minaret which hleb Is II very err rich In is most moat Intimately connected with the tho gold A specimen 11 from the tho Combination analysed by hy Dr Ir proves to be b a n of ot copper CO antimony and arsenic which HO Mo 1 fur far M as A qualitative composition goes may he ho Tellurium U is nl RI so 10 present prent In ore and the Mine IM element has haa h been reported elsewhere In the district Therefore heltor the ores orel also all may be b very ery er rich Moreover while the difference between the ozi oxidised and the portions portIon of ot the ores within the ti zone sone of o o oxidation Is II In general so great certain shouts 1 oc occur o occur cur a A as In hi the January and Ind the Jumbo where the quartz quarts In hi I this th w somme ne la is of extremely high grade aad Such luh ore or appears to be I mostly pint pyrie but In view of 01 the fact tact that tellurium Is ii I found In the district It I la Is very VII possible that gold Ild telluride may my be b present fn It I there I fore tore appear ap lr probable p bbl that the th rich rh ext ores orl owe their thi thel richness not n primarily pr marily to concentration during ion though hough this process has h certainly been ben very 1 important but to the t ex cx e at t f sheets sheet of ot rich noh antecedent sulphide ore or OK OJ Concerning the origin of or these te sul lul sulphides phidel It I Is II probable that thit pome m tea I far tar farns faras ns as 11 can now no 1 he be seen len are lUl purely pur primary while others othera otherl have been formed fonne sub nub to the main maui of the reef f as a In III the tle Combination mine Heie nela tit the rich auriferous sulphides have formed In a broken soon aone Ine In the barren baren reef ref anti and occur Our OurI as I seams Mams and often ns as 01 coatings on the pebbles J In the braccia brac The question arll arise rl ee however asto to whether the sub lb was WOR the result of 01 descending or ascending amending waters ater Concerning this hi the evidence Is not conclusive but there lh Is I no n evidence that those these t rich ore orel have he been concentrated from the lean len antecedent quartz quarts mass The mUl presence of elements like arsenic antimony and tellurium In the sulphide ore or suggests suggest a I le et origin OF OP BISMUTH Besides Dl l the t e elements mentioned above bismuth bl muth occurs In iii the tho ore or In Inthe Inthe the January It occurs In the oxidized ores or In hi the form of silvery scales which Is II as a determined by Dr bismuth perhaps the oxide In Inthe Inthe Inthe the Combination long fong needlelike crys crystals lucia 1111 have been heart found fo I I I which according to the manager Mr Col Collins Una give the J l c I It 7 r t i J I chemical tests for tor bismuth sulphide The fhe silvery II vry mineral above noted Is ii sometimes sometime found foum In the January arranged In long lon forms forma und unil |