MODERN MINING AT ALTA UTAH LEROY A PALMER IN MI MINES ES AND MINERALS Z alta the center of the little cottonwood utah is situated in a cleft of the wasatch range some 20 miles from salt lake city as the crow flies at present the nearest point of railroad connection is at sandy the smelting smelling sm elting center distant some 16 miles from wasatch and 23 miles from alta formerly a branch of the rio grande western vestern railroad connected wasatch with sandy but of late bears years this has fallen into disuse and is partly a r t I 1 y dismantled the camp of alta is reached from wasatch by passing through the ahe 4 mile narrow gorge cut through barren granite by the L little i t t I 1 e cottonwood creek some 2 miles below alta the first sedimentary rocas r 0 c K s overlying aver lying the granite extend to the ottom bottom b of the canyon and thereafter the gorge widens to quite an extensive expensive open flat entirely I in the limestone the he elevation ot of the carlp is some with the sale of one of its greatest producers alta is a camp remarkable for the vicissitudes of fortune through which it has passed twice it has been destroyed once by fire in 1873 when it was rebuilt and again three years later by a tremendous which without the slightest warning buried the cam camp ap and hundreds of miners be aal q aj the columbus consolidated mill alta alia utah feet while the surrounding peaks ascend to from 1000 to 1500 feet higher yet these peaks rearing their jagged outlines against the azure sky have made the camp famous tor for its scenery historical 1 to the era of virginia city pioche odie bodie and their contemporaries belong this historic utah camp once it was famous on 0 continents for the richness of its mines 0 later iter infamous for the scandal associated neath its weight this last was a disaster from which recovery was slow many of the miners who escaped unhurt left the camp in terror of their lives and to this day dal alta bears the reputation among miners as a spot accursed alta was not rebuilt until I 1 later years in this connection it is of interest to note that on the 1 morning of january 20 1906 a from an entirely unexpected place killed six men bringing the total number of deaths in altas history from this cause alone up to fig 2 reproducing an old photograph taken at the continental alta mine shows the depth delih of snow remaining on the ground at the time of taking the photograph in the ahe middle of may fig 3 9 shows the present state of development of this property the beginning of the camp dates back to the year 1867 when soldiers from fort douglas at salt lake city made the first mineral locations unfortunately for the discoverers the troops we were re transferred and the claims passed by relocation into the hands of prospectors to whom the soldiers had shown ore specimens rich ores of lead silver and copper were found at the grass roots and the camp which was quickly founded was productive from the start the presence f a thick growth of fir timber on the mountain s slopes lopes and water furnished by two large streams meeting within the town limits made the mining conditions favorable the chief drawback of the situation was the great altitude entailing severe winters and great depths of snow which often cut communication with the outside world for weeks it is noteworthy however that such was the richness of the first opened deposits that considerable ore was profitably shipped during theme these wl winters n aers by V ST over the snow the most famous mine of a score of these early prodoc producers ers was the emma the story of the richness of its ore and the scandal involving a united states ambas both copper an and d sulphur in association with lead and silver ores an and d these were the constituents which largely increased in the ore in addition the tiza tion of silver in 1873 and its subsequent 6 n 04 V vt S the starting of the main tunnel of the columbus consolidated several years ago attendant on its sale to english capitalists ita lists is one of the most interesting in mining annals besides the emma the flagstaff a name not free from taint the lavina grizzly prince of wales city rock yankee blade and a score of others added their rich ores to the output of the camp and increased its fame the population of the camp in the early seventies was about 5 souls some teams were engaged in hauling ore and supplies to and from wasatch at prices of 10 per ton down and 20 per ton up this large traffic at lucrative prices led to the early construction of a 7 mile narrow gauge mule tram built into the solid rock of the hillside and covered with a heavy timbered snow shed the entire distance to wasatch this tram represented an expenditures of but it gave an ore outlet unobstructed ted by snow slides on its completion the moved its ore aerial tramway the first built in this section of the country several years of uninterrupted prosperity followed foli owed which witnessed the sale of the emma mine before mentioned in june 1872 a serious cave in on this property blocked operations and the cessation of dividends led to the investigations which proved it apparently a worked out mine mine resulting in its shutdown shut down in the fall of 1874 from this time on various vicissitudes led to the rapid deehne of the camp the ore bodes in many properties were lost while in others the changed character of the ore found on penetrating the d sulphide zon zone G led to abandonment the smelters shelters sm elters then pen decline in value made few of the mines then profitable the which wiped out the camp in 1876 dealt the region the final blow and although mining was carried on in a desultory way for some years until about the flagstaff mine grew tobe the smelling smelting sm smriti elting center of the intermountain country and a with its improved methods no langer anger aerial pen iced eted copper and sulphur in 1901 tony jacobson a practical miner of years experience reopened the old yat yan kee blade mine an dother adjacent claims bv by means of a tunnel driven into the mountain from a point near its base in a years time tin the tunnel progressed a thousand feet and the ore bodies opened up led to the tion of the columbus consolidated mining company prompted by the success of this company the continental mines and smelting smelling Sm elting corporation or po ration was organized by henry M erow crow ther a mining engineer of salt lake city this company acquired four of the old mines together with a number of adjacent claims about a mile above the town and started Us its operations in july 1903 at what became known as the continental alta mines these two companies blazed the way for others and one by one the old mines were reopened till today the activity of the camp reminds the old timers of the early days geology the UL attention Lention attracted in the mining world by the revival of this famous old camp makes data concerning its geology and economic mining of interest especially as little of technical nature has been written on this district geologically speaking the ore bearing strata of alta and the main ore bodies are but little removed from the granite basal 10 A tic A pleasure party going up the old alta tramway the me region reg was then totally deserted with a single exception the years intervening until 1901 saw a vast change in the smelting smelling sm elting industry the small smelter early established at sandy by formation in fact important ore bodies ea both in granite and at its contact with of 01 quartzite and limestone the little cottonwood canyon from its mouth to alta at the head of the gulch is as regul t as the leaves of a book and presents a ale fold with a general north and south axis greatly eroded both at apex and west limb practically no mining is done on the valley slopes of the wasatch range Tri primarily marily because the limestone or ore bear ing strata is eroded almost entirely away to a great depth below the slopes of great i salt lake valley just below tanners flat the first sedimentary rocks the lower quart are seen crowning the granite and dipping regularly toward the head of the canon four i miles above or near alta the lime stones that lie on the quart reach the bottom of the canyon and thereafter the canyon which here broadens to quite an extensive I 1 open flat is entirely in limestone and upper quartzite and this series of strata constitutes the mining region the thickness of the total limestone strata as exposed is probably in the neigh intrusion of denuded laccolite lac colite of granite and of considerable extent in contact with limestone the columbus quartzite referred to corresponds in geological age to the ontario quartzite of park city while the flagstaff and continental lime stones bear a similar relation to the silver king limestone of the same camp the same system of diorite dikes extends from park city to alta the erosion at park city in the vicinity of the mines has been deeper ally considered than at alta and the strata that have bene rained mined in at alta represent that which is eroded at park city accordingly broadly speaking mining at alta has only been prosecuted to barely the same depth as the outcrops of ore deposits at park city the distance separating the main ore regions of alta and park city is but feet hence the relation of these camps to each other is very marked f lip na AA looking down the south fork of big cottonwood from the divide above alta of 2600 feet and is assumed to be of lower and upper carboniferous the lower strata or that which lies on the quartzite is of a blue and white banded structure and on this strata rests the columbus quartzite some hundreds of feet thick overlaid by the upper lime stones more than a thousand feet in thickness the upper lime stratas are also with black and limes this upper mass of limestone is a regular series of distinct layers the thickness of the separate bands varying from two feet to dozens of feet and the whole sloping from 34 to 40 degrees into the north side of the canyon or to the northwest the limestone is traversed by numerous diorite dikes and is extensively fissured it is these dike contacts in some few instances j abut but mostly the fissured region of sediment hy 1 tary strata that bear the ore bodies at the V extreme head of the main gulch there is an topographically considered the most elevated mining at alta begins at a horizon of feet above sea level at the continental companas comp anys upper workings and extends down in this property to feet in the lower tunnel the deepest workings in the camp are at the columbus consolidated beginning at an altitude of about feet and extending down to feet above sea level while the deepest mining at park city the daly west and ontario begins at about feet elevation and extends down to about feet above sea level this alta mining has proceeded no deeper than higher than the most elevated outcrops daly west in park city this feature is further emphasized by the fact that all alta mining is tunnel development while at park city it is mostly shaft development this matter is discussed simply as an interesting te comparison the field of which requires too much data by actual survey a and fl d study by geological comparison of strata for the scope of a short article but it suggests that united state geological survey work might well include both park city and alta districts as a geological whole ore occurrence the principal ore bodies of alta occur in limestone and mostly in fissures but there are also contact or of strata deposits that seem independent of fissure influence though such ore is of lower grade than that in the vicinity of fissures and dikes the porphyry dikes or masses of eruptive e rocks of the district are not themselves valuable for mineral as some in bingham nor does the ore often follow the dikes that is the main ore hodies bodies are not on walls of dikes at the contact with sedimentary rocks the principal intrusive dikes are nearly vertical and cut the limestone beds at nearly right angles to their strike the fissure system has about the same general strike and dip as the dikes or northie northwest gt and southwest with 65 to 80 degrees dip to the northwest or the same as at park city of which district alta is a well defined continuation the fissures in most instances bear ore only where they cut certain limestone strata whose composition is the most favorable for ore deposition all the limestone is not favorable ora ble to ore bearing but only an occasional layer or stratum which is doubtless of the most carbonaceous or calcareous composition t on intervening layers being more are not not so favorable to chemical dissolution and replacement by ore deposition accordingly as the layer of the most carboniferous and calcareous limestone is thick or thin so is the ore channel which penetrates it large or small in some places where the fissures cut these layers favorable for ore deposition the limestone is mineralized or wholly replaced by ore for a distance of from 2 feet to feet from the fissure these fissures are very persistent and even when penetrating strata unfavorable for ore deposition hold their course and are strongly marked even if very narrow at points where the fissures cut the ore bearing strata the ore body often extends for a considerable distance upwards rarely downwards in the fissure above the ore bearing lime strata should this occur at a point where a flat ore shoot or one which extends in the direction of the enclosing lime strata is not strong and continuous the inclination of the miner in the past has been to follow the fissure ore along the level or dip of the strata until the ore sooner or later pinched down in this way the main ore channel has been often lost as in the case of altas most famous producers if instead of bf proceeding in the direction of the strata enclosing the ore at points where the ore body became the miner has followed the fissure either further up or down until it again penetrated ore bearing strata new ore chutes would doubtless have been developed these fissure deposits are usually from 4 to 6 feet thick horizontally while vertically the size is limited by the thickness of the enclosing lime strata in some instances however the ore bodies are of great size being 60 to 80 feet wide horizontally and 40 fe feet et thick vertically early day mining in the camp resulted in several main ore channels being lost and some unwisely spent effort made to relocate them but as a rule little was done except the extraction of the main bonanza ore bodies practically no intelligent new exploration was done until recently there is a notable absence of faulting in the district and this being so it would seem that ore channels could not easily be lost but practically all early day mining of the camp was in oxidized zones at shallow depth and as such ore is not so well marked as sulphides sulp hides it is thus more difficult to follow in addition to the fissure deposits the various forms of contact deposits must be mentioned although of minor importance contact ore deposits between quartzite and lime exist on the columbus property while in the continental alta mines deposits occur at the contact of diorite and limestone this latter deposit however is a flat shoot following certain limestone strata irrespective of the dip of the igneous dike which is nearly vertical the contact deposits are usually about 4 feet thick and seem to extend throughout the district at intervals enclosed between certain strata these bear ore apparently irrespective of fissure influence and are not so high grade as the fissure deposits several such deposits as yet undeveloped carry 2 to 2 per cent copper in sulphide form with 1 to in gold and silver oxidation practically all the ore coined in early days in the upper limestone was completely oxidized containing less than one unit of sulphur and even that small