Annual report . the south. The ore is largely of the red porphyry type, asso-ciated with which is quartz in lenticular masses and ribbon-like structures. 34 Department of Mines No. 4 Brecciation of the ore is evident in the fractured character of the porphyry andthe vein quartz. Minor slip planes occur along the ore body and commercialvalues sometimes cease at one of these slips and come in again on other slips indrifting along the vein. Constant assaying of faces is necessary, since the oresometimes turns off, from where it has been following a well defined wall, diagonallyalong another wall.
Annual report . the south. The ore is largely of the red porphyry type, asso-ciated with which is quartz in lenticular masses and ribbon-like structures. 34 Department of Mines No. 4 Brecciation of the ore is evident in the fractured character of the porphyry andthe vein quartz. Minor slip planes occur along the ore body and commercialvalues sometimes cease at one of these slips and come in again on other slips indrifting along the vein. Constant assaying of faces is necessary, since the oresometimes turns off, from where it has been following a well defined wall, diagonallyalong another wall. In addition to the fracture planes with which the ore is associated there areheavy faults showing much clay gouge in places that in part have followed the orebodies, and again are not near the ore body. One of these faults was drifted on for210 feet easterly from the cross-cut on the 2ti0-foot level, being mistaken for the 300 200 100 0 l__i I I I I L Scale: 300 Feet to I Inch 300 /r / R ^ LA ^, /V-^J^.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
