| Show DRY PLACERS OF SOUTHERN california by chas S haley from the time of the days davs of the mexican colonies when alta aita california as it was then called was a province of the spanish crown gold has been won from the dry placers of the desert the indians in the days of the padres used to bring in gold to the missions which was laboriously recovered from the desert washes by the crudest of methods unfortunately however there is no reliable record of production until comparatively modern times but we know that in total it amounted to many millions of dollars since the american occupation of california we have somewhat of a record however and we know of districts which have produced from a hundred thousand to two millions of dollars all won by hand methods and most lyby laby dry washing for this reason it seemed to the present invests investigator clyator in preparing a volume on the placer gold resources of the state that there might still be a possibility of obtaining an economic economic return from these placers by the application of large scale working Ny methods and that it might in some cases justify the bringing of water for some distance to cover the ground however the results of this investigation which has covered every district of importance in the desert have on the whole been vary very disappointing and the writer is forced to the conclusion that these placers acers have already been exploited by the only practical means the mexican with his little hand operated bellows and hopper the reasons for this conclusion will be given herewith southern regions conditions explained from the standpoint of geological history the district south of the tehachapi has been distinctly different from the region of the great valley to the north the ranges of subsidence and elevation have been much less during tertiary and later times during the ithe lone ione and later transgressions chich covered the foothills foothill Is of the western slope of the sierras band and the coast range this begoin was comparatively quiescent for this reason it may be assumed that the topography and to some extent the climatic conditions of this region during the time at which changes were taking place to the north old did not vary greatly this fact leads to a vital difference in the manner and amount of deposition of the gold in the desert channels so far as it occurs alono along the line of channels whereas it in the north we have a primary concentration from the erosion of the and of the sierras to be followed later by a of the values in the tertiary streams str Ilis by the present or quaternary drainage running in many cases normal to the older in the region of the de desert sert we have an entirely different condition and one not nearly so favorable to the concentration of gold in large quantity and d persistent amount uld did in the south the drainage during tertiary times evidently not greatly vary from the present lines roughly allty all of the deposits on which stream action had ba d the slightest earing bearing may be classed along the drainage lines of ancient streams whose courses follow the general direction of the modern ones such as they are in some cases the ancient ones es seem larger than those of the present day in other cases ses smaller in san diego county we have a course which commencing inen cing in the Cuy amaca mountains near julian and the banner district runs down through ballena via hatfield anu and coleman creeks which have crossed it and caused local forn ala ia mining E engineer san francisco calif in mining in call california state mining bureau publication for july co concentration down through t ramona and the san vicente region and finally empties into the ocean somewhere around la jolla this region is not of economic importance as the values were very spotty according b to the records of the districts and facilities for working are limited to a very short season of the year east of this in imperial county we have either local erosion deposits like that in the borego coun country which is said to average about fifteen cents a yard or the deposits in the Chuc kawalla basin the chocolate mountains the eagle range and the country north and east of desert center these were all more or less tributary to the drainage system of the colorado which is probably one of the oldest rivers rivers on the western slope on the colorado itself or ne near a r I 1 it we have the potholes potholed Pot holes at laguna the picacho basin and other deposits in the blythe parker ehrenberg region these were all investigated b by the writer and his conclusion is that although a recorded production running into the millions has come out of them little remains of interest to either large capital or the small miner character of deposits the gravel y or eroded material was very spotty and seemed to carry the in the stuff at some distance above bedrock and any pumping scheme which might be used to get water would be so costly and cumbersome that the ground will never pay it back the mexican with his little portable machine and jack of overhead in moving from 6 gulch to gulch where the greatest concentrations were ha had d the only feasible system the picacho and lag laguna bu na deposits are and slates for the most part containing quartz stringers from which the gold has come in both cases the erosion caused by the colorado river at the base of a low range of hills has resulted in the accumulation of this material the river wash itself does not carry much value but the disintegrated matter above carries it and the erosion of present day gulches has resulted in local concentrations which were worked by the mexicans coming down from the owens lake country along the eastern base of the sierras was an ancient channel which may have come through red rock canyon where it was joined by another flowing eastward from tehachapi by way of jawbone canyon turning easterly its course can be traced by way of goler and summit diggings from here on it may have gone one by way of copper canyon to long range and COO Cool coolgardie gardie there to lose itself near barstow in the present channel of the mojave another portion of this system runs from the stringer district down through st elmo wash where it is still being worked in a small way by hand band dry washers another comes down goler wash in the Pana mints this channel or system of channels is one of the best known in in the south and illustrates by its physical characteristics a point which strikes the writer very forcibly in its bearing on the possible economic operation of these gravels work of rescue at the mine is being directed by three mining men who have had from the beginning ginning tie the benefit benefit of advice from some of the most experienced miners miners mi mining ning engineers and specialists of the west stream gravel practically valueless As a rule the stream gravel which consists of well rounded boulders of crystalline rocks from the sierras carries no value at all wherever it crossed a belt of containing quartz stringers 6 or any body of olivine bearing or other basic rocks by local erosion erosion is is pro produced deuced in connection with the heavy cloudbursts which swept down the gulches intermittently local concentrations of gold As 1 a result at goler one can notice that the shingling b of the washed material is transverse to the general gen era I 1 direction of the course of the deposits heavy gold is found near the tops of the ridges and from 30 to 60 feet above bedrock and on local false bed rocks of clay and disintegrated cs at summit diggings intensively worked on account of its shallow depth during early days a scheme is now proposed of bringing in water involve miles to cover the deposit the same thing is is proposed at coolgardie Cool gardie with a fifteen mile water system As the concentrations have long been worked out by hand methods and the general body of the deposits will only run from fifteen to sixty cents a yard it Js is considered a waste of time and money to carry out either of these ideas in lytell creek along the line of the santa fe there was a local concentration from stringers in the granite this has all been worked out A little water was available here the last of these very interesting systems consists of a channel which coming down from placenta Pla cerita canyon ca rivon near newhall with another branch which headed above bouquet canyon crossed into san francisquito Francis quito and came down somewhere sherebell wh erebell bellow ow piru to be joined by another course which came from lockwood by way of piru canyon it was impossible to work out the definite course of this system but the above is a fair approximation this was much worked in the early history of los angeles and ventura counties count ties but as even the gave it up as no longer affording them a living it would not be advisable for a white man to try it the values appeared to be concentrated on the points of the present hills and in the gulches quite ai a little water was available for working this system it must be ren remembered in estimating the gross production of this as well as other regions re b ions in this part of the country that a large part of the work was done when wages b avera averaged b ed a dollar a day in times of industrial de depression many men making a a bare living at best preferred to be their own masters white while doing it and the aggregate of all their earning presents an impressive figure considering the leno length th of time involved and the number of men employed employ ed it is is no wonder that the aggregate amount even from very poor diggings b was large air separation processes a proven failure gnp final point that has irn impressed pressed the writer and with particular force is the total and absolute failure of air separation processes when applied on anything larger than a hand scale two monuments to this failure still stand in mournful state one at goler and the other at coolgardie Cool gardie limited capacity and imperfect separation are the main reasons A machine which will work on a laboratory scale with material which has been dried on a hot plate certainly will not be a success when applied to the general run of desert material especially after a shower has moistened the ground the material simply balls up on the canvas tables further machines of this character are so cumbrous that they lose the chief advantage of the hand machine its ability to be transported from one spot or concentration of gold to another as soon as the pay has been worked out the most successful method of handling this material in the judgment of the writer is one which was tried out in the brandsburg randsburg Rands burg district some time ago it consists in the use of a very little water and the constant saving and return of the same for re washing this venture broke even 9 on four dollar ground when water cost a quarter cent a gallon and had to be hauled five miles the cost of one in preparing this article the san gabriel and the bear and holcomb valley deposits li have ave been omitted as they do not come under the head of dry or semidry semi dry placers miners inch which in the north countr country y is supposed to move one yard of ground under proper conditions would be thirty six dollars a day at ait this rate if the water were not returned in the method referred to a sluice about seven feet long and fourteen inches wide is given a head motion by an eccentric and driven by a two horsepower gas engine the sluice has a false faise bottom with holes immediately behind the hungarian riffles fiffles rif fles the material is wheeled and shoveled in after boulders have been screened out the water carries out the fines on about a twelve inch grade into a wheelbarrow which stands over a pit the wheelbarrow is punched full of holes and the water is drained into the pit from it it it is then pumped back by a centrifugal pump which is run by the same gas engine from a countershaft through the false fali bottom where it jelts up behind the riffles fiffles to perform its service in carrying the material through the sluice again the only loss of water is through evaporation and absorption the riffles fiffles are always kept open by the uplifting jets of water and the concentrating motion of the eccentric head makes a very effective ji jig of the whole affair to the writers mind where any water at all is available this process of separation has all the air processes on the market completely distanced but it can only be applied on a small scale to ground which will run from four dollars up and in his experience there is so little of the desert placer which will run this amount per yard that it is practically negligible |
