| Show future of East Tintic District I I From the 1919 report of the United States geological survey Work Vork In the lc Tintic Standard and East Tintic Development mines has proved that ore ha has been deposited there in considerable considerable considerable con con- quantity In rocks that in the Tintic district proper lie west of ot the four ore zones and are regarded as relatively unfavorable for ore deposition The mild degree of metamorphism in the limestone limestone limestone lime lime- stone less than a a. mile south of ot these mines together with the tho presence of dikes and small irregular Intrusions of ot porphyry indicates a minor center there as the most probable probable probable able source of the tho ores In the East Tintic Tintic Tin Tin- tic district The solutions from this source however had to ascend through the Cambrian quartzite before reaching the limestone whereas In the Tintic district district dis dis- proper they passed from the main mass directly Into the lime lime- stone Owing to the nearly horizontal position of the sedimentary rocks in the East TIntic district the shale formed an effective barrier to the ore solutions that rose through the quartzite and I owing to the low degree of ot permeability of ot both bolh these rocks the solutions spread along the shale quartzite contact formIng forming formIng form form- Ing for for forthe the most part thin layers of ot low grade ade ore ie with local small bunches of ot high grade ore Only where the rock was sufficiently shattered at the intersection of or northerly fissures with easterly faults I or cross breaks was ore deposited in int I large t shoots along or near the contact I Where fIssuring was sufficiently strong to i. i afford passage upward through the shale shae the solutions reached the limestone limestone lime lime- stone but the above the shale are not so favorable for ore deposition a as the that contain the main 2 ore 1 zones c ln In the Tintic district Ore In commercial quantity however as shown b by the East Tintic Development vein and perhaps also by the ore In the new Tintic Tintic Tin Tin- tic Standard shaft was deposited along pronounced fissures fissure especially at their intersections with cross breaks and lo local lo- lo cal replaceable beds and detailed work wont wIth a view to l locating the principal f fissure is- is sure zones u and d uhe the purest limestone beds bedsore may result in the discovery of additional ore bodies The solutions on passing through the shale were not only depleted d of part of ot i theIr f metal content but were cooled and 1 diluted m wm with waters already in the limestone lime lime- I I stone factors which lessened their power I to form extensive replacement deposits Such solutions may travel considerable I distances without finding a a. favorable I I place to deposit ore and may therefore give rise to small scattered shoots 1 re remote remote remote re- re mote from the source of or Instead of continuous ore bodies Such scattered deposits are characteristic of other parts of ot Utah where similar conditions conditions con con- existed and may be expected in the of the East Easl TIntic district for tor some miles northward from the present present present pres pres- ent productive mines Ore characteristic of ot such solutions Is comparatively low In silver sliver and Its deposition Is accompanied accompanied accompanied by relatively little The finding of new ore bodies obviously obvious obvious- ly depends in largo large part on a detailed study of the district to locate the prIncipal principal principal prin prIn- cipal mineralized northerly fissures and cross breaks the shale quartzite shale te-shale content and the more replaceable limestone beds It should be borne in mind however that mineralized fissures In outcrops of limestone limestone lime lime- stone and especially in the rhyolite area area may be he a long way from deposits of commercial com corn mercial size and not directly connected with such deposits Reference to the geologic geologic geo geo- logic map PI I in pocket shows that I the sedimentary rocks are dislocated by easterly and northerly faults of ot considerable consid consid- I erable enable size and older than the rhyolite There are strong chances therefore of miscalculating the tho depth of the quartzite shale contact When the distribution of ot known ore oro zones in the tho TIntic and East Tintic districts dis dis- and their relations to Intrusions are considered It is reasonable to expect that at least one more zone may exist between the East Tintic Development De De- vein and the Iron Blossom zone but results of prospecting p g at shallow low g depths In this area have th thus far I been negative The existence nce of or ore zones I beneath the tho rhyolite east of or the Tintic Standard zone is also a possibility but no evidence of of the I rhyolite rhyolite lite sufficient to serve as a guide In prospecting has been noted |
