Laserfiche WebLink
South Nonh <br />~- Oltler tlikes ~ <br />Urad ore Glder <br />~~ body porphyry <br />.~ <br />~ ~' ~ ~-- Rrd Mtn. <br />A level porphyry <br />~1_____ _ <br />Silver plume Mein fissure fault <br />granite host- ~;~~-~- <br />7.35-1.40s 109 Years ._ - -- -=_ <br />~~~ <br />Henderson Uratl Henderson Primo; Hentlersun <br />mining level poi ore body por' gramie <br />Ages of inr~usives (M.Y.1 <br />Older porphyries 2'r.6 ± 2 9 <br />Red hloumain 270'_ 3.0 0 600 it <br />Hendrrson granite 2s.3 - 2.5 kd <br />Scale <br />The 8,106 production level main drifts are developed on 60 It <br />centers. Cirawpoints anc crosscuts, un 40~ft centers, are stag <br />gered on each side of the haulage drafts. Air intake raises and <br />ore passer: are located on 320 fl censers. <br />Slightly arched, 12 x 12.3~tt production drifts are supported <br />with resimgrouted rootbolts and shotcrete, and sized rock paves <br />the roadways. <br />A rhyolite porphyry stock complex of tertiary <br />age Intruded the Precambrian Silver Plume <br />granite that Corms Red Mountain. Related <br />quartz~molybdenite mineralization occurs <br />within the stuck complex The orebody is <br />bounded by hydrothermally altered rhyolite por <br />phyry and has a shape similar to an elliptical, <br />Inverted, canted teacup. The arebody is 3,000 x <br />2,200 ft In plan, antl varies between 400 and <br />800 ft In thickness. The long axis is oriented m <br />a northeasterly direction, antl the orebody is <br />canted such that minerah::ahon extends to <br />greater depths along the east and south limbs. <br />Molybdenite occurs in a stcckwork of quartz <br />MoS. veinlets, wdh the gradational hang <br />ingwalls and tnotwalls deterrnlned by assay lim <br />its and economic considerations. Based on a <br />0.2090 MoS~. cutoff, present reserves are 303 <br />million tons of ore averaging 0,499'0 McS;•- <br />making Henderson the highest grade cooly <br />mine in Amax's holdings <br />The final decision [o develop the mine was <br />made in 1967, following i:ompletion of dia~ <br />mood drill coring of 27 holes lolahng more <br />than 100,000 ft. Coring of some 250,000 ft has <br />been completed so far. <br />The crosscuts are drivon l2 tf wide x 12 ft high, while draw <br />points are concreted to 10 x 10 tt and reduced to 8 ft high at the <br />brow. From each drawpoint, a crosscut is driven at an angle cd <br />45 for the first 22 ft and then perpendicular to the axis of the <br />production drift. <br />Ramps between levels grade from 6°e to 15% and measure 12 <br />x 12.311 to the undercut level and 14 x 13.5 ft for all others. <br />