Arizona republican., 1899-03-31

| Besides the Congress vein, described i above and upon which nearly all the work has been done. there are several others Of great promise on the surface and holding out well to the extent of 1 the development work that has been ] done upon them. The principal Of these is the Niagara vein, running nearly parallel with the Congress, but, unlike the latter, seeming to be entire 1 Iy enclosed in the granite without the
 accompanying dike which is such a marked feature of the Congress vein, Preparations are now being made to
 thoroughly explore the Niagara vein, with view to largely increase the ore output. A crOsscut is being run
 from the Congress workings on the
 1,3375-fOOt level to cut the Niagara vein.
 and a new shaft is being started ton
 the OutcrOp), which will be pushed down to a connection with this cross
 cut on the vein at the 1,375-fOot level.
 There are already two shafts on the
 vein-One on the Remnant. 250 feet
 deep. and the other on the Why Not,
 150 feet-bOth showing the vein strong
 and continuous to these depths, and
 carrying ore which gave concentrates
 assaying fifteen ounces gold and fifty
 five ounces silver The high silver is
 a peculiarity of the Niagara vein dis
 tinguishing it from the Congress, the
 concentrates from which carry over
 ounces of silver per ton.
 There are numerous smaller veins
 carrying good ore and running approx
 imately parallel to the Congress and
 Niagara, but none of them have been
 explored to any extent.
 Ore.-The Congress ore is white
 quartz. carrying very pure iron pyrite. generally disseminated through
 it in small particles, but at
 times in quite massive form. There is little if any gold ill the quartz showing no pyrite, and hardly any free gold exists in the ore. The pyrite carries on an average about eight ounces of gold per ton. Other sulphidss so commonly accompanying iron pyrites are notably absent, lit tie galena of very rare occurrence be- ing the only one Identified. and chemi- cal analysis of the concentrates from ! the ore showing hardly trace of cop per arsenic anthony, or indeed of 1 but iron, sulphur and silica. !
 The Niagara ore, on the other hand. . shows considerable galena and some copper minerals besides the iron py- rite. This difference seems to be rather . of the ore of this neigh bOrhOOd when the veins are entirely in . the granite as distinguished from those which are accompanied by the green stone dikes.
 As stated above, the ore in the Con- gross vein is generally near the foot wall. Its position and appearance sug- gest that it occupies what have been he exceedingly Hat lenticular cavities produced by a fracture of the dike llong the plane of it's dip, followed by 'uH:cient movements along the line of fracture to leave such cavities by req son of the Inequalities of fracture. There is no evidence of the replace nent of the greensboro by quartz, the whole appearance being that of the filing of pre-eXisting cavities by depo- ! itiOn from mineral waters. The valu- ble contents of the vein have been ] uite likely derived from the green tone by segregation and infltratiOn. The above hypothesis regarding the ( rigin Of the vein is somewhat ( trengthened by the fact that no clear y defined ore shoots have yet been ob- l erVed in the mine the ore being jn ] at bodies with lMore apparent rel -