CHAPTER IV

THE GENESIOLOGY OF GOLD

(AURIFEROUS LODES)

Igneous theory formerly strongly upheld--Quotation from Rosales--His arguments combated--Hydro-thermal action--Its evidences in New Zealand--Professor Lobley’s theory--Author’s deposition theory confirmed--Later works--Conclusions of Le Conte--Metamorphic slates and earlier Silurian strata theory--Format ion of mineral lodes--What was gold originally?--Metal or metallic salt--Silicate hypothesis preferred--Explanation of sulphides and silicates of gold--Bischof’s interesting experiment--Skey’s and other deposition experiments--How gold took its metallic form--The Comstock lode--Occurrence of gold in shutes explained--Why lode junctions are usually rich--Cox’s theory--Instances of lodes re-forming--Gold as natural sulphide--Newbery’s theory of gold in pyritous lodes--Probable occurrence in pyritous ores as sulphide pp. 34-47