| Show A geologists G eo logist S opinion rb n of silver ling kins n consolidated J J beeson mining geologist 0 of salt lake cikity made an expert examination ot of the silver king consolidated soli solid dated atod tunnel and the following la Is a part ot of the tha report as aa published by him in a recent issue ot of the salt lake mining review a my examination ot of the geology in the spiro tunnel ot of the silver kin king 9 consolidated mining company at park city utah was made between april esth and april 1921 1 I have at no time during my experience sn in the examination ot of alnea visited a property where more careful work has been done not only in the engineering but also in the collection and recording of CeD geologic logic data As tor bior the spiro tunnel I 1 believe i that it Is one of the finest bluest pieces ot of engineering and mining work that has been done in fit the west the tunnel is now in a distance ot of about feet and irom from its position it la Is very obvious that should the opportunity be offered other properties could operate through the spiro tunnel to the mutual advantage ot of all parties concerned the chief events of the past that appear to have had an important bearing on the general and structural geology may be summarized zed as follows since the close of the tha cre cretaceous period during Intermit taut intervals the wasatch mountains haave been elevated probably during the eaily part ot of this elevation great brosure was developed which exerted its maximum force in an ea and westerly direction As a result of thia pressure gentle and syn folds were developed in the vicinity of the present park city mining district while further to the west irr in the vicinity of 0 the little cottonwood mining district certain structural condiff condl flous lons weakened the strata and great oNer thrust faults occurred following the period of folding and faulting just mentioned a zone of weakness was developed by deep seated forces farces extending across the state of utah in art an east west or slightly northeasterly and southwesterly wester lym direction the easterly extension of this zone of 0 weakness is marked by the uintah mountain up life while to the west ot of park city it Is indicated by a series of 0 great stocks dikes and masses of di orites mon and closely related igneous ous rocks t between park city and alta these crocks rocks are exposed on the surface in a continuous belt some two miles in width aud and below the surface this belt ot of igneous rocks probably connects I 1 with the little cottonwood stock which bich extends from alta to the mouth j jot of the little cottonwood canyon still further to the west the same I 1 zone one ot of weakness is suggested by the r northeasterly south southwesterly westerly dikes and masses ot of igneous rocks that cut cuta ithe 1 the oquirrh mountains near the I 1 bead ot of bingham canyon li along ace the borders of 0 the intrusive igneous gneo us masses in some soma localities the sedimentary adl strata appear to have made lade room for or the with but ut little deformation but tor for long instances along the borders aspect j ally lly in the little cottonwood and park ark city districts there lias haa boon boen a 0 marked doming ot of the previously ormed formed structures turea thus ahns in fit the vi inley of 0 park city the antiel lual and synclinal yn olds folds have apparently been tilted to the north this folding and in my opinion Is largely re tor for the position llon of 0 the park ark city limestone in the spiro tuti tun liel acl I 1 there is a possibility that abat there has laa been some eoma faulting tault lne between tho the spiro tunnel and th the most moat westerly esterly workings in the silver king coall tion lon property but considering cons dering the direction ot of the average dips that lave been taken during the driving of t the tunnel it dw not appear to be e necessary to assume mint this be lias teen been the case cabo in order to explain the relative position ot of the park city Mm limestone estone la in the two properties f in any event the structure endl atas that the park city formation hlll be ba above tho the spiro tunnel to he 9 most southerly and westerly limits of 0 the property in the zone he 4 to the greatest t amount ot of euln cioll should occur this will jo the case unless there has been faulting alting beyond the present taco face ot of alie he tunnel ore bodies in this ay are ara typical silver load lead replace ment deposits in fit the limestone and the character of the formation ap pears to be the controlling factor lu in the deposition furthermore it la Is an established tact fact that similar sil ver lead replacement ePla cement ore bodies occur in the lime stones in the cottonwood districts thousands of feet below the park city formation where there Is evidence indicating that the deposits formed at much greater depths below the surface than any of the deposits of the park city district yet explored from indications I 1 have observed in the park city and cottonwood districts there Is good reason to believe that the full adjustment of the strain along the zone of weakness heretofore described was not completed with the intrusion of the igneous masses but continued to manifest itself iby by fissuring and fracturing during and following the fica tion of the magmas hagmas in attributing the fissuring to the adjustment of a strain along the zone of weakness rather than to the local conditions and local strains set up by the cooling magmas hagmas I 1 wish to make it clear that my belief Is based on actual findings rather than a merely arbitrary bf belief or idea |
