. Transactions. k whichthey cut is due to penetration of the latter by calcite, which isintercrystallized with secondary albite, formed at the expenseof the original feldspar. Veinlets traverse the rock in different directions, but the OL061 01 i in rai LDH ILL ORB-DBPOf til I L 50 1 neater pari of the filling ocean in fissure-like openings con-stituting two well-marked Bystems. One set of fractures Btriland dips approximately with the structure of the enclosingslates: the other, which is the more prominent, strikes slightlyoblique to the Btructure of the country and dips in the oppositedirect
. Transactions. k whichthey cut is due to penetration of the latter by calcite, which isintercrystallized with secondary albite, formed at the expenseof the original feldspar. Veinlets traverse the rock in different directions, but the OL061 01 i in rai LDH ILL ORB-DBPOf til I L 50 1 neater pari of the filling ocean in fissure-like openings con-stituting two well-marked Bystems. One set of fractures Btriland dips approximately with the structure of the enclosingslates: the other, which is the more prominent, strikes slightlyoblique to the Btructure of the country and dips in the oppositedirection, that is, toward the southwest In places where tin mineralised dikes are narrow, the set oftissuree parallel to the country-structure usually diminishes inimportance, and often only the cross-fractures have been devel-oped. This may Ik- explained upon the supposition that thetendency to motion parallel to the walls of the intrusions wastaken up outside of the massive rock in the >lates, while the Fig. This dike, about 3 ft. wide, is cut by veinlets of calcite and quartz, which filltransverse fractures. The breaks extend into both walls, but the filling neverextends far beyond the dike itself. Dike of Albite-Diorite in Open Cut of Ready Bullion Mine. transverse strain affected both the slate and the intrusive rock,the latter being specially susceptible to cross-fracture becauseof its small mass and brittle nature. Cross-fractures, filledwith vein-stuff and limited to a narrow dike in the slates, maybe seen to good advantage at the east end of the Ready Bul-lion pit, near the southernmost outcrop of the diorite (Fig. 12).Throughout the mines it is the rule that all transverse gash-veins stop at the walls of the diorite, and while there are a fewexceptions the quartz seldom penetrates the country-rock toany great distance, and when it does it diminishes rapidly inthickness. However, this is not always due to the non-continu-ance of the fissures, for they may be frequen
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
