Show THE ALUNITE DEPOSIT NEAR MARYSVALE in the december issue of the mining review there appeared an article on alunite near marysvale Marys vale being an abstract from the press bulletin sent out by the LT S geological survey mention of the fact that this commodity had been discovered in quantity and in remarkable purity in utah aroused general interest throughout the united states and this interest has been intensified by the further fact that the ille survey has since gone fully into the subject in bulletin which was in general circulation only a short dilme a ago go the text is by B S butler and hoyt S gale who state after a brief introduction that alunite has long been used abroad as a source of potash alum which it resembles in chemical composition the alunite contains a relatively larger proportion of than the common potash alum it is insoluble but is readily converted to either the soluble potash alum or potassium sulphate by a comparatively simple process of heating or A process that has long been established corn com ercia lly may doubtless be adapted to the american deposits the marysvale Marys vale deposit so far as now known is not of such magnitude as to afford a source of all the potash salts now consumed in the united states but it may prove to be an important factor in providing an american supply that will perhaps be especially available to local and western markets particularly in meeting the demand for higher grade salts possibly also the greatest importance of the commercial development of this deposit will be in the added stimulus it may aff afford ord to exploration for other similar deposits of this mineral especially in this general region and it is on the discovery of such other de posits that the provision of a home supply from this source must depend location and railroad facilities the newly discovered deposit of alunite is situated near the head of little cottonwood canyon about seven miles due southwest west of marysvale Marys vale piute diute county utah it is located in and near section 16 township 28 south range 4 west and so far as known is covered by mining claim locations marys vale is the present terminus of the sevier branch of the denver rio grande railroad the deposit lies high in the tushar range outcropping cropping out near the top of the ridge separating north fork of little cottonwood Cot onwood creek from the main branches of little cottonwood canyon the vein and wall rocks form the crest of the high ridge leading up to the main divide the deposit 7 aar A IWO venes V va r F 4 ai edna crater or geyser near northwestern outcrop of Alunite photo by will C higgins ranges efrom approximately feet above sea level to about feet at its present recognized lower end which is about feet above the railroad at the marys vale station character C har acter of the vein the alunite of the marysvale Marys vale deposit lies principally in A large banded vein cutting cutt 1 ng at steep inclination tile the volcanic rock or andesite which forms the greater part of the tushar range the view given in plates 1 and 2 were taken november vember r 2 1911 and show the character of present development work and vein at the outcrop the smooth rock faces shown in these views are fractures across the vein the large vein is evidently a fissure filling and not a replacement of the country rock as the main body of the deposit is remarkably pure and has the banded or crusted structure of a typical fissure vein that replacement has not produced the larger bodies of alunite is further attested by the fact that the main vein contains but little silica while in the wall rock where replacement has occurred the quartz cheno crests remain practically aly unaltered and silica that has been set free from the decomposition of other minerals has not been removed the real attitude of the vein is not yet very clearly defined the vein banding is assumed to be approximately parallel to the walls and if this position is continuous below the part at present exposed the vein is probably nearly vertical in its northern extension and has a distinct dip about 60 degrees southwest toward the south end of the recognized deposit crystalline material is generally clear pink to reddish in color and the finer grained reek reck varies from a white to a decided pink the fine porcelain like material of which analysis 19 is representative is seen under the microscope to be a granular mass composed of irregular crystals of alunite through this fine grained material are scattered small ve inlets of more coarsely crystalline alunite the coarsely crystalline portion of the deposit of which analysis 18 is representative shows the more distinct crusted structure the crystals are show a distinct cleavage and are of a rather coarse granular or tabular form yielding a splintery fracture in the mass of the rock quoted from danas textbook of mineral ogy agy for comparison analyses of alunite from deposit near marysvale Marys vale utah 18 19 dana AIO 0 P foals 0 trace trace soa 38 34 PO PA 58 50 KO 1046 nao 33 56 F 0 1290 1308 10 I 1 0 09 11 sio 22 1000 number 18 is a selected specimen elmen of the U V 4 I 1 A AR V f I 1 wj 4 ED aae cr ta yr plate no I 1 trench crosscutting cross cutting main alunite vein plate 2 view of the trench shown in plate 1 I from the opposite direction on each side of the main deposit smaller veins or bands of alunite alternate with similar of much ciuch portions of the wall rock which in place contain iron sulphide in disseminated grains or crystals physical character of the alunite the larger bodies of the marysvale Marys vale alunite P ate are of unusual size and notably free from foreign material the alunite occurs in massive form being in part a fine grained compact rock breaking with conc holdal fracture and having a porcelain like appearance but containing also considerable masses with a distinctly crystalline structure A considerable part of the vein material at the outcrop however is more or less of an amorphous texture and commonly sheared to a foliated or schistose structure the the elongation of the crystals though show ing hig a tendency toward radiation in tufts v is however roughly parallel and is normal to the vein banding and the walls fc A considerable portion of the alunite as revealed in the present prospects has an amorphous texture and a more or less schistose structure which may in part be due to weathering but probably is largely the result of shearing movements in the mass of the rock chemical character of the rock the chemical character of the rock is expressed by the following analyses of some of the best and apparently purest P material collected at the prospect pits these analyses which were made by W T schaller show a very close approximation to the theoretical composition of the mineral as supposedly best material it consists of clear pink coarsely granular crystalline rock number 19 is a selected specimen of a light pink very finely granular rock of almost porcelain like fracture and no distinct structure located claims the principal claims located on the marysvale Marys vale alunite deposit are the ouster custer group shown on the accompanying plat taken from the official surveys PI III this group of claims adjoins patented mineral ground and recorded claims both to the northwest and southeast as is indicated on the map the custer group covers the greater part of the alunite deposit as now recognized the first location made expressly for the alunite having been staked january 1 1911 property to the northwest of the ouster custer claims is said to be covered by mineral locations under the control of the florence mining alining milling company lessee of the utah gold mountain mining company including the so called log cabin property and also the patented ground known as the bradburn property southeast of the custer claims is the patented ground of the clyde property indicated on the plat As yet only what is understood to represent a single large vein deposit of the alunite has been shown by the developments on the marysvale Marys vale properties proof of the actual continuity of this deposit beyond the area of most numerous prospects in claims nos I 1 and is not complete the vein appears to be limited by fairly well defined walls and to follow a very regular trend extending nearly due northwest and southeast As the outcrop and openings are all approximately in the course of this same general trend it is likely that they represent one and the same vein although it is possible that there are more than one possibly related veins there is some evidence indicating that other deposits may exist but at present it is believed that none have been opened by prospects far from the main deposit the representation ot of the outcrop of the alunite on plate III is probably only approximately correct as it is based on a very hurried compass traverse made at the time of the visit to the property on november 2 the extension of the alunite deposit along the course of the vein to the southeast has not yet been proven beyond the outcrop shown on the plat float has been found on the lower claims of the custer property and this may indicate the existence of some rock in place but it can not now be said with certainty that the vein extends farther southeast than Is in the custer claim no 1 the deposit has been recognized northwest of the custer claims however where it occurs in massive outcrop apparently very similar in character to that portion of the vein that has already been prospected this northwestern outcrop is situated on the crest of the ridge north of the log cabin tunnel and about feet above it near the edna geyser it is probably half a mile or more northwest of the limit of the outcrop represented on plate III the apparent continuity of the vein on the surface and its vertical range of outcrop from an elevation of somewhat more than feet to about feet may be assumed as good evidence of a corresponding continuity of the deposit in depth however some considerations which are more completely reviewed in the discussion concerning the probable origin of these deposits tend to indicate that some alunite deposits are of superficial origin and will not be found to be continuous in depth As will be aseen however the evidence in regard to the marysvale Marys vale deposit is thought to favor a deep seated rather than a superficial origin and the conditions of the deposition of the alunite may not have been dependent on a close proximity to the surface or on any immediate relation 01 to the topography of the present time thickness of the main deposit the prospects completed at the time the vein as it was exposed in the trenches were made but most of these were far from satisfactory owing to the incompleteness of the exposures the size of the vein and the apparent purity of the material are probably its most unusual features according to a number of measurements made from the present developments there is in one place at least I 1 C 71 0 CC I 1 0 4 2 CZ 01 C j C 0 00 ell V Z L C 41 cz 1 I 28 sa fj 4 V j L 1 I plate 3 showing the principal group of claims on the marysvale Marys vale alunite deposits of the last visit to the property had traced only about to feet of the outcrop which is that portion indicated indicate dby by the outcrop line of the meander traverse in plate III only that portion of af the vein that is covered by the prospects in claims nos I 1 and 2 can be said to be known with much certainty here numerous measurements of twenty feet of solid alunite in the larger vein and six feet more in a parallel vein some twenty five feet to one side with considerable sid erable quantities of alunite rock and alternating terna ting purer alunite and siliceous wall rock intervening the lower grade rock may possibly extend beyond that shown in the present pits other measurements made reveal less thickness but in each case it is doubtful whether the trenches that have been dug expose all the alunite that may be present with the exception of the outcrop of alunite near the edna geyser already referred to the norther northernmost most put outcrops crops examined were in the prospects indicated on the plat as nos 1 and 2 in custer claim no 15 alunite was observed in talus and specimen no 1 was collected at an elevation at least seventy five feet above and southwest of the prospect marked as the discovery on the ouster custer claim no 14 it is likely therefore that more than one vein of the alunite will be found near this locality but at present the prospect only incompletely reveals the one vein A 10 foot hole and shaft exhibit six feet of apparently good material without showing distinctly that both walls have been reached the alunite is massive of texture which varies from coarsely crystalline to fine including some sheared material specimens 6 and 7 and the block that was afterward analyzed no 19 were collected near the shaft and monument marked SE end center custer no 2 and NW end center custer no V I 1 here the development consists of a 30 foot trench crossing the crest of the ridge together with a shaft about twenty feet deep much aluch alunite has been thrown out on the dump the trench shows ten feet of apparently very pure alunite and five feet at the north end of the cut composed of mixed vein and wall rock however a considerable portion of the trench is cut in loose surface material and probably does not show tile whole thickness of alunite at this place this is the locality illustrated in the views shown in plates I 1 and II 11 northwest of this point two other prospects were visited distant about and feet from the end center monument described bed specimen no 18 the analysis of which is given was collected from the nearer trench here a cross section of the alunite vein measured fifteen feet with no apparent partings or inclusions of other material the farther trench showed twelve feet of solid alunite but the exposure is probably incomplete as it runs into slide material at either end A fifteen foot tunnel just below this trench exposed a stringer of alunite apparently an orf offshoot shoot from the main vein as it differs markedly from the vein in direction and pitch about feet southeast of the northwest end center stake of ane custer claim no I 1 is an open cut showing a solid face of somewhat more than twelve feet of massive alunite varying in texture from coarsely crystalline to fine granular the west wall of this vein is a dense quartz or siliceous rock containing specks of iron sulphide and beyond this at least six feet of alternating alunite and siliceous rock are exposed the trench ends in slide rock about feet southeast of the northwest end center stake of the custer claim no 1 is a trench thirty to forty feet long cut transverse to the course of the vein which follows the crest of the ridge at this place here or banded structure of the vein is quite distinct and from the attitude of this banding the vein is assumed to be dipping 60 degrees SW and to have a course N 50 degrees to 55 degrees W some of the ore exposed here has a beautifully clear banded crystalline structure and is of pink or reddish color A detailed tape measurement made allowing for a CO 60 degree dip as indicated by the banding gave a total thickness of seventeen feet six inches of apparently solid alunite with at least ten feet more of alunite and siliceous wall rock in alternating bands exposed in the northeast end of the cm cat about feet southeast of the trench last described is a deep trench or open cut and shaft exposing at least twenty feet of solid alunite vein rock the banding here strikes N 50 degrees W and dips 60 degrees SW there are some very massive blocks in this exposure and the whole section exposed would afford an excellent opportunity port unity for taking an average sample the extension of the cut to the northeast shows admixture with the siliceous wall rock in part highly stained with red |