Show big and little cottonwood BY I 1 MURRAY SCHICK two features of supreme importance the one scientific and the other commercially have marked the history of the big and little cottonwood mining districts salt lake county utah in the last year the first was the clearer interpretation of the geology of these districts the second the development of an ore deposit which rivals in munificence the very best of the good old days po mining writer salt lake city the two events are correlated both resulted from the same operations the scientific phase is given precedence in 1 n this article because its ultimate effects seem destined to overshadow the discovery of any one mine be it ever so rich with the key in our hands we can unlock not only one but many of natures na treasure vaults in demonstrating the presence of a mammoth in the south fork of big cottonwood canyon the cardiff mining company turned the spotlight spot light on the relation ship between the canyons of the big and little cottonwood creeks established the geological status of certain unclassified ore occurrences and translated into working terms the topography of a large and little known mining area the early bonanzas of the cottonwood district such as the flagstaff vallejo emma and grizzly lay almost in a line running southeast and northwest along the north slope of and parallel to the canyon success of the prospectors along this zone gave rise to the theory of a mother lode or master fissure as the primary source of the ore bodies discoveries within this zone were looked upon as the legitimate fruit of applied knowledge while strikes to the north and south of the line were regarded as fortuitous occurrences attributable to good luck rather than to good management accumulated facts tended to shake this theory and it was modified from time to time until some of the later writers came within hailing distance of the actual conditions geologically perhaps the riddle was solved but it remained for the cardiff to explain the method of the solving a geological riddle hereafter no one will look in the east west fissures for the primal source of enrichment rich ment these will be regarded as secondary to the north south fault fissures delineated at the surface by gulches branching southward from the main canyons of the big and little cottonwood them the part played by the east west breaks in the dissemination of the mineralizing mineral izing agent was that of troughs to carry away the overflow from the parent outlets or in some cases that of obstacles to hinder the pursuit of the metallic treasure for there is evidence of at least two periods of east west fissuring one before the rising of the magma and one afterward during which many of the ore bodies previously formed were displaced the so called mother lode of the early days now appears to have been nothing more than one of the older fissures which because of its unusual size and its soluble wall retained great quantities of the mineral fed into it by the interesting faults both the soluble lime and the shale and quartzite took part in the conservation of the metals the lime acting as a sponge to receive r it and the shale and quartzite as dams to retain it even where the ore bear ing lime has appeared at the surface we have a right to assume that at some epoch there was a capping of schistose material which prevented the escape and of the precious magma in ane light of recent discoveries in the cottonwoods Cotton woods we can define with considerable precision the geological conditions most favorable for the deposition of large ore bodies these embrace a fracture running approximately north and south and deeply of width and fissure faulted a transverse depth and a contact between soluble and the formation at the insoluble members of crossings of the faults and fissures thus a bed of soft lime with a shale hanging wall and a quartzite in juxtaposition to tile the master fault would be an ideal structure in which to prospect for ore these conclusions impart to the southern cottonwood canyon an interest forks of big instead of using they have never held bield before a transverse fissure as his prospecting base the miner of the future will direct his operations from the dominating faults although such a change of attitude may no re veal ore deposits which would not have been disclosed ultimately by tile the old method we are justified in hoping that it will shorten the time and reduce the cost involved in the exploration of this field the discovery in the cardiff in the case of the cardiff the ideal conditions described are apparently reversed for we find the ore replacement between a lime and a quartzite hanging wall but from the surface outcrop farther down the canyon we have a right to anticipate thai the lime will be found to rest on oil a floor of shale the cardiff strike was made in the last quarter of the year just ended for almost two years the cardiff mining milling Com company had been working dilli gently upon a long drift tunnel intended to gain depth on an ore shoot of moderate dimension opened some years before by a tunel bunel at a higher elevation starting in the lime the bore was driven southeasterly small stringers showing mineral were cut at various times but on the whole the showing in the tunnel was disappointing up to the of october on that day without preliminary indications the shots broke into in e to a face of crushed carbonate ore between lime and quartzite in the following two and one half months the tunnel was extended feet in ore the space between the walls widening constantly until I 1 th they P y were more than forty two feet apart how much more cannot be stated until more crosscutting is done galena appeared in the carbonates at feet and grew into a streak nine feet wide which passed diagonally across the drift in the opinion of cf some experts the galena was molded in tile the transverse fissure running northeast and southwest and cutting the south fork fault every days development changes the dl di mansions men of the demonstrated ore body tout but as this is written january 5 the apparent width of the vein at the first crosscut is thirty feet the word apparent is used because there is evidence that the lime foot wall is not a permanent wall but a rib or horse in the vein beyond which may lie a further mass of mineral thirty five feet south of th 11 first cross cut a second crosscut has been driven twell ty five feet to the right and twelve feet to to the left without the discovery of even an apparent wall at the hanging wall end of the first cross cut a drift has been sent out along the wall at a tangent from the main tunnel and at the end an inclined raise has been lifted seventy two feet midway in the raise a round of shots blew a hole clear through the lime exposing ore on the other side the ore has been opened for five feet and the distance to the permanent wall cannot not even be conjectured at feet the tunnel passes out of tile the ore but is apparently about to br break eak into the lower reach of the fissure from which all the former shipments of the cardiff were made via the upper tunnel assays essays from froin the face of the drift along the hanging wall average 57 per cent lead 23 ounces silver 75 copper and about 2 gold at the top of the raise on oil the nominal the metal contents are 51 per cent lead ounces silver the tunnel is feet vertically from the surface and 1000 feet from the surface on the pitch of the vein the cardiff has taken out as much as fifty tons of ore in three shifts and it would be almost as easy to ship tons ina day if transportation facilities were provided there is a fairly good road down the south fork to the main canyon and there a splendid turnpike runs in to the valley A short distance below the mouth of the south fork in big cottonwood canyon is the old maxfield mine from whose miles of drifts a million dollars worth of ore is said to have been mined standing alone far from any other producing property the maxfield has hag been looked upon as a geo logical orphan now it is distinctly classi fied as a beneficiary of the fault from which the cardiff derives its riches the same fault and its intersecting fissures are to be credited also with tie the surface i deposits in the old mines of the south fork such as the carbonate howell bran borg and kennebec and it places the tar baby midway of the fork in a desirable position tracing the fault the fault has been traced over the dil divide l to the little cottonwood canyon and even beyond toward the american fork alin eral area the south fork or superior fault fis sure is but one of four parallel faults running south from big cottonwood Cotton wod within ads tance of two miles they are beginning at a the west the south fork days fork allver fork honeycomb Aidi although ough only cial ore deposits have been found in these thes faults it is a noteworthy fact that the great grea est of the alta mines were found 0 over V ertha j ridge exactly opposite the leads heads of octile the ifould I and silver yorks forks A line from day s 1 lead gad tot to the lie flagstaff and a line from silver to the emma mine anine i I half way between the silver and honeycomb faults occupying the relation to the silver fork that the maxfield does to south fork is tile the famous prince of wales mine which eclipsed the maxfield in its yield ot of silver picketed on three sides by bonanzas of glorious memory it is not strange that day s and silver forks are being looked upon as among the most inviting of the undeveloped formations in the whole wasatch range especially since the cardiff has dem oust rated conclusively the dominating influence of the north and south fault fissures on oil the enrichment of the district in day and silver fork in days fork the days fork mining company financed by a few salt lake professional fess ional men is prospecting for the fault and in silver fork the alta aita tunnel transportation por tation company headed by fred V bodfish has driven a deep tunnel 1000 feet into the divide parallel with and only a short distance away from the silver fork fault this tunnel is now heading through the soluble white lime characteristic of the prince of wales workings and has had stringers of mineral rich in silver copper lead and gold the property is equipped for a drive of one mile which will carry it under the divide and underneath the little cottonwood mines the maxfield in the main canyon below the mouth of south fork has been leased and optioned option ed to a syndicate headed by F H Vahren camp whose plans for ing and developing the property seem thoroughly practicable on the alta aita side on the alta aita side of the divide the largest production of the past year has been made I 1 by the south hecla operating on the wedge I 1 fissure at the south side of the canyon in the fiscal year ending october 1 it marketed tons of ore for which it received from athe the smelters shelters sm elters in following its ore westerly feet it has provided large ref serves of ore and this drift has been connected with the working level below by three raises on the vein october 1 the company had more than in tho the treasury and no debts other alta producers in 1914 were the michigan U utah tah alta consolidated cabinet wasatch mines company and the K P the michigan utah output was made by the cliff clif L mining company lease and was maintained regularly through the summer the alta consolidated company found the best ground of the year in inthe the closing months and looks forward to enlarged production in 1915 both the flagstaff and columbus con properties of the wasatch mines company have been active and lessees lessels of the latter have marketed several carloads of high grade ore from a contact vein on oil and above the tunnel level A threefoot three foot face is being followed in the drift and by a raise the cabinet is under lease its ore was taken from an old 45 foot shaft and a tunnel is being driven to gain depth on the vein the K P is in peruvian gulch running south from alta the ore there was in small quantities but of excellent grade some ore was developed during the year in the sells property west of the south hecla lessees lessels of the west toledo have been prospecting their ground through the frederick tunnel late in the year an option on control of the columbus extension was obtained by A 0 jacobson and associates and work started in the tunnel which is feet below the level of the cardiff workings the wasatch utah between the mouths of big and little cottonwood canyons having found amalgamation and cyaniding cyan iding too costly to work their low grade auriferous ore is about to try a new method of treatment some 50 to ore has been developed in one of the workings on the ridge north of big cottonwood canyon the giles M M company is conducting a winter campaign and obtaining encouraging values in silver and copper unless all signs fall fail the big developments of the coming year in the alta district will be on the south side of big cottonwood canyon between the maxfield and honeycomb gulch and these developments will prove a powerful stimulant to mining operations throughout the cottonwoods Cotton woods |