| Show production of gold in the united states although detailed statistics for the production of gold during the last year are not yet available mr waldemar lindgren of the united states geological survey has made some interesting prognostications as to the distribution of the production among different classes of ore deposits A preliminary estimate of the production of each state and territory was given out by the director of the mint at the first of the year according to this estimate the production of gold in the united states during 1904 amounted to after a period of very rapid advance in the gold production from 1892 to 1900 inclusive clu sive during which an increase from to took place there were two years of nearly stationary output and one year of decided decrease it is therefore very satisfactory to find that the production of the yellow metal has risen again to record figures the estimate being against for 1903 mr lindgren finds that the sources of this increase are easily traceable in the first place cripple creek the greatest gold mining camp of the united states has gained about due to renewed mining activity following the successful completion of a new drainage tunnel the cessation of the strike which interfered with the production of 1903 and new discoveries of rich ore bodies in the second place a new mining district of great promise named goldfield has been discovered in nevada and this during the first year of its existence has added at least to the value of the output for that state in the third place the production of california has risen nearly compared with the production of 1903 this increase is due in considerable degree to the wonderful development of the dredging industry in the sacramento valley lastly the smelting smelling sm elting of auriferous copper ores has received a great impetus in utah augmenting the gold output in that state by these four factors together with moderate gains in the production of alaska montana and south dakota are sufficient to account for the increase of nearly in the production of the last year compared with that of 1903 mr lindgren classifies the gold production according to its derivation from placers dry or ores copper ores and lead fresl ores he estimates the production of gold from placers as from gold and silver ores at from copper ores at and from lead ores at making a total production of a sum that practically agrees with the estimate of the director of the mint alaska is the largest producer of placer gold and should show a gain of at least the output being estimated at california will show an increase which may reach the production being estimated at this is partly due to a favorable season for hydraulic mining but chiefly to the great development of the dredging industry unexpectedly large areas in yuba sutter nevada butte and sacramento counties have proved suitable for the dredging process while the dredging machines have been greatly improved and enlarged and the expenses correspondingly spon reduced at the same time the output due to drift mining and hydraulic mining is on the whole slowly decreasing idaho montana colorado and oregon have probably maintained their production at the value reached for a great number of years during 1903 these states respectively yielded and since 1902 new mexico has contributed over annually in placer gold derived from veins of unknown age and obtained by dredging operations in colfax county but none among the other states has exceeded 1000 oo in output the production of gold from gold and silver ores is subdivided by mr lindgren into the production of pre cam brian quartz veins of mesozoic quartz veins in the pacific coast belt and of tertiary gold quartz veins vein s in the rocky mountains and great basin making a total of auriferous quartz veins of precambrian pre cambrian age are so far as known confined to the atlantic states south dakota and wyoming the bulk of the yield from the atlantic states comes from north carolina south carolina and georgia and is derived from gold bearing pyrites in south dakota the great low grade deposit of the homestake Home stake mine is considered to be of precambrian age the small production of wyoming should probably also be credited to the same class of deposits auriferous copper ores occur throughout the united states in deposits of widely differing age and form some of the greatest copper deposits however such as those of arizona and michigan are practically free from gold the gold from Cali fornias copper deposits is estimated at and from copper ores at approximately the mining of auriferous copper ores in utah has received a great impetus during recent years and the production of gold from this source has steadily increased it is estimated at for 1904 but this includes some of the smelting smelling sm elting ores from tintic gintic which are apt to contain both copper and lead the gold from copper ores in colorado is difficult to estimate as no exact statistics are available but it probably does not am to amount lount from colorado and utah come the cipal gold bearing lead ores colorado prin n tributes about oo of gold from con c lead ores one fourth of which is deril derive it from the leadville mines utah gains about abom led of gold from lead ores nearly the ih entire amount of which is obtained from the rt park city silver lead veins e these estimates are set forth by mr lindgren in a paper which is included in the surveyors bulletin no entitled contributions to economic geology 1904 |
