How To Prospect

Yon follow u p fclie inountain sido iintil yon come to whcre the primitivo rock is lolt bare. Abovo this yon muy look tbr fissure veins. Jii8t bclow tlie point ot contact belween . tlic se lïnicntary rocks and primitiva rocks you ma y look foi" contact Vfins. Therichest deposita occur in Colorado it tlie point of junction of tbc silurian anti azoic or primitivo rocks, altliough gome good cont:ict ioiles havo boen found on the California coast in the later jurassic and sirussio roc.vs. In snch cases au erosión of silurian and gubgequcnt deposition took place in the inezoic perioil. As a rule, however, look lor the riiliost contact lo.le wliere the liluriau have ïviiiiinod to protect the mineral. As the conLact deposits Ijecotne exposod, the mtioit of the air anl ot' the carbouio acid of the liniCiitoiie irall rocks gradually metainorpliose 1 the mineral iiom its origui.il cüiiilitiou 111 to curoonates anu free-gold aud sil ver. Tiie exterior portions ot' the fissure veins aro also ot'ten partially metaiiiorphosed, so that it trequoutly happens thjit lissure veins show ing easily mili ing ore at the rarfaoa turna out to be pure sulphurets, arseuides, and antimonides, at a depth ot' sixty or ono litin Ired fee t, and tlie milis i'requeiitly erectad ut great OOSt. nioniuueiits ot human folly, have to be Ruandoned and smelters orected. Carbonates are tound in the deep lissure veins bccause the air iind car bon io acid could not reach the mineral to traustorm it froin the hard lineltiDg gulphides, urseniiles, etc, into easy snielting carbonates ana freo metal. It is not ahvays that thu contact loiles contain rich ores, sometiines ore almust barren in silver, at olhor times theymay be t'ull ot' liorses, wedges or lnumnocks, and koys and slides, is in