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Show CONCERNINGECP MINES. Piyablo ore n filll fnuud In lht deepest (told mln)7 ' of tho world tfcotio of Colorado, CallforbU and Vic-iorln, Vic-iorln, Australia, says tho Mining and Scientific Press. Thu Utter aro down f.000 feet, with pav ortlll In sight. Tho dnnpn.il Cu!tforula'S,tnu Is down l6out 2 $00 feet, v.HU idfd'ore lnho lowest level. on f i.,orndo -hotls lilio jitm iriited In !o llio 2.UI.II' leM I, and the, mines still un- pnjn rnus. At wliul level me we t et tin in to In-comu In-comu buirtn? lliii it 'iso niiiv 1m-come 1m-come iiiiprolltKble b. imi' nt In-creasid In-creasid i).prei. wlilb1 tin- inluu ut thu ore roiutduv the snuie us sbove. On tho Kiiiid, in tlie TrntnSi tml. tor In-stntite. In-stntite. th gold-be.'.rln bbitiket emi-tlmiCK emi-tlmiCK to prod urn IH-Hlly tlm "uiiui av-erago av-erago allies us aluiie. whllo tho expunge, ex-punge, of mining iuercisus as thu luv. els mo nulled to deeper and Mil! deeper luiels. this being dun entirely to ecoiiomln and not geological conditions. condi-tions. A careful review ot nil that is known of tbo genesl ot oro deposits, and paitleularl) of i-prnndnr.i enrichment, enrich-ment, leads to thu luevltablu conclusion conclu-sion that thero still icmuliis much to learn about both nrlflnal mid t-ufund nry oru deposits. At ono tlmu roc-ondar) roc-ondar) enrichment was not recognized recog-nized ns an lmp.it tant factor in milling, mill-ing, but u study of tho ritiuirknlile phenomena of the on dipislts ot Huttc, Muni., forced tlie conoluBloi. uiion the observing rnglne'.is tliat 111 rich oro bodies of some of tho vgiuX mines of that district were due wholly to secondary enrichment. No ono now doubts that thu phenomenally rich oro of Prycr Hill, nt Leadvllle, Colo., Treasure Hill. White Pine, a score ol places In Arizona and Ncwida mid elhcwherc, were due to similar rausos Thu gold mines of California owe their surface richness to tho mini cause. Tho notably ilcli deposits at Ooldflcld, Nov., must bo ascribed to (bis secondary enrichment, as must almost every oilier occurrence of unusually un-usually rich oro at or nenr tho surface. |
