| Show wo ajo 1111 sel wow wl I 1 the geology je of alta by Bw bano arthur E snow no E M i i j lot lot lot 1161 ti M owl since the days when the emma flagstaff prince of wales and many other properties of less renown and prom pro mience lence ceased pouring their wealth into the pockets of their owners and others and since that winters day when an avalanche of snow moved the town of alta from the bottom of the canyon up on to the adjacent side hill there has been but little heard and less ARTHUR E sow SNOW E M written concerning this once celebrated mining camp which formerly counted its population by the thousands and produced dollars by the millions so far as the writer is aware that which has been written in regard to the geology of the wasatch range near this section applies in a general way to the whole range and not to any particular locality the report of the emma mine investigation affords some light but is not bred enough in its ils scope this being the case and as the writer has had no opportunity for detailed investigation since this task of writing was imposed the reader mu must st look for nothing of a scientific nature in what follows at present the government has engineers in the field making a critical study of the district comprising park city alta and the vicinity surrounding both but the result of their investigations will not be published for some time to come when it is issued it will undoubtedly show a very intimate relation between the two camps and to some extent develop the fact that within twenty five miles of salt lake city lies another district that extends the greatest promise to the miner and prospector according to the observation of the writer alta and park city might well be treated under one description for what applies to one camp can usually be said of the other although alta is somewhat higher than the park and nearer the divide that separates them and for this reason has been probably somewhat more disturbed by the core that forms the backbone yet in general the formations are similar though erosion has had greater effect on them at alta where they were more broken off in earlier geologic time after the great wasatch fault was made alta and park city or the locality where they now stand probably constituted disregarding minor irregularities a great inclined plane sloping eastward subsequent erosion together with the other disintegrating forces of nature have materially altered the aspect and today a water shed separates the districts and little cottonwood canyon has been carved out where the strata are exposed in a splendid manner beginning at the mouth of little cottonwood ton wood with your face eastward and traveling up the canyon one passes between I 1 high granite walls for several miles before the sedimentary strata are encountered aey having been thrown far to the eastward ty by TP great mass that now forms the west face of the wasatch range at that point As alta is approached the sedimentary rocks are seen on either side of the canyon in great strata dipping to the east at a steep angle this angle in general decreasing until at the divide east of the old townsite it is not more than thirty degrees from the horizontal in some cases however the strata are standing almost vertical the general strike of the contact is N 40 degrees or nearly at right angles to the course of the canyon these sedimentary rocks are among the oldest and are in some cases highly meta morph lc le they consist of lime stones quartz ites etc Lime stones greatly predominate and vary in color and texture from the white coarse crystalline to the dark close grained highly mineralized variety just west of the old townsite are two strata of black schistose chi stose lime separated by about abbit two hundred feet of quartzite at a distance its weathered surface has the appearance of a black volcanic lava the coloring being due to a large percentage percenta gD of pyrites of iron it is highly sill sl licious clous as are all the lime stones of the district and is almost a as s hard as the quartzite with which it contacts co the columbus consolidated mining company under the management of tony jacobson is driving a tunnel through this lime to cut its contact with the overlaying quartzite and if indications may be relied on it will soon be repaid for its trouble passing on eastward over the edges of white and blue lime strata and the contacts on which the emma flagstaff lone star and other noted properties are located one a great reef standing near the head and just at the south of the main canyon which has thrust itself up through the strata and thrown them in a manner beyond description on its west slope the quartzite and iron copper bearing schist ore dipping under the granite which would indicate a fault or a complete fold ot of the strata indications on the north side of the canyon incline one to the former theory at the east base the same strata are dipping at an angle of about thirty degrees to the northeast and under a massive white limestone cutting through these strata at about right angles to the strike are a system of mineral bearing fissures and a white quartz porphyry dyke about fifty feet wide the fissures have been exploited to some extent but have never been developed where they cross the stratum of iron copper bearing schist which has alime a lime for a hanging and quartzite for a foot wall work is now being prosecuted with this end in view and with flattering prospects of developing one of the biggest low grade copper mines in the state what influence if any the porphyry dyke has had in the of the fissures is difficult to detect it is apparently the youngest intrusion in the district as it cuts everything e else in its course down the canyon without an exception the mineralized fissures are strong and as a rule continuous as is instanced by what is known as the big fissure which can be traced for fully a mile on its strike there is being considerable prospecting done in the locality during the present winter more than has been done before since the great fall but little is being said about it if the camp does not respond to the vigorous work that is being performed then the writers judgment is at sea and he be will not know where to turn for more en enticing i dicing prospects |
