Show SORTED AND SAMPLED along the mohave desert and the death valley region of california are numerous small deposits of low grade borax which will doubtless be utilized in the future there are at present several persons in nevada who are working the cotton hall ball surface deposits a venture that before the increase of the tariff on borax would have been wholly profitless near winnemucca nev are two surface deposits of earth overlying old marshes and carrying about 15 per cent of borax which are working during the summer months one of the best methods for the ventilation of small mines is the use of a stove or fire box placed at the mouth of tunnel or shaft this stove or fire box should be constructed so that it made air tight connected with it is cheap piping that reaches nearly to the face of the tunnel or to the bottom of the shaft A fire is made in the stove and the air furnishing the draught must necessarily come through the piping in the tunnel or shaft by this means the smoke and foul air is quickly drawn out by many this method is much preferred to that of pumping air into the mine while all are not known to be associated with ore deposits says a well known writer yet this form of geological occurrence has come to be regarded as affording possibilities that should be inquired into wherever found so many valuable mines and extensive mining districts occur in colorado nevada south dakota utah and elsewhere in association with intrusions that it is now considered necessary to investigate the contact of rocks with the surrounding sedimentary formations which they intrude even in mineral districts all are not associated with ore bodies it is not generally known but it is not so tiresome to turn a crank or wheel as it is to use a hammer in the use of the hammer and drill it is estimated that the man with the hammer hamme r develops about foot pounds while in turning a crank he develops foot pounds and it is stated that curnin turning a crank with resistance well balanced wi with ih a fly wheel is a bet better way of utilizing a mans strength than by direct hammering machine drill makers are now nov perfecting hand drills for mining work the mistake was formerly made of endeavoring r to produce hand machine drills to compe compete 4 e with power drills it was not recognized recognize d that there was a good field for small light r drills to utilize a miners strength in to tie the fullest degree there are now several small hand machine drills on the market the occurrence of deposits of ore in what are termed chimneys is accounted for 1 several ways where there is no ledge nd where no extensions of such ore de decosi post lons ons are to be found it is safe to assume hat such chimneys of ore are to be account fed d for by the action of hot springs either active artive or long ago extinct one authority in n commenting on such occurrences says ascending ing hot spring waters if bus may deposit different ores with a certain order of vertical distribution ascending hot alkaline waters passing through zones 0 or r crushed and reopened opened re beins eins containing pyrite react re act with the iron sulphide and zinc lead copper and silver If f present are precipitated as sulphide As tending sending hot acid waters may leach the lower ower levels of reopened opened re veins and carry ing ng the minerals to higher levels deposit sold gold silver and copper upon cooling in the supper apper portion of the vein the grand canyon of the colorado river bays ays the mining and scientific press is in arizona izona Lr about 70 miles north of williams a i station on the santa fe railroad it is W cabout bout feet deep on the north side and bout about feet on the south side the difference 1 being due to the southerly dip of the 1 sedimentary edi rocks which form the greater portion of the walls of the vast chasm it is s from 12 to 20 miles in width the top most lost stratum is of carboniferous limestone the he bottom of the greater portion of the canyon anyon is cut down into precambrian pre cambrian crys talline illine rocks in some places lava flows ejected from vents on the carboniferous platform lat form or in still later rocks have flowed to the edge of the gorge and poured over the ie side into the abyss a cataract of mo molten tell rock ack which filled the canyon to a depth of bout about feet through this accumulation of E debris the sand laden waters of the colo rado ido river has again scoured its way cut ting ng down once more into the underlying rocks icks ores of copper and gold are known to occur in the crystalline rocks at the bot tom m of the canyon and in the limestone and quartzite uart zite near the bottom of the sediment tary iry series lead silver ores are found but the ie topographic conditions are such that as s yet little success has attended the efforts to mine in the grand canyon |