PLATE XXIV. Economic GEoLoGyY. VOL. XIII.

Fie. A,

MAGNIFIED 390 DIAMETERS.

Bornite and chalcocite replaced by chalcopyrite and chalcocite. The late
chalcocite lines the chalcopyrite vein labeled Cp. B, bornite; Cp, chalco-
pyrite; G, galena; Q, quartz.

Bre Be

MAGNIFIED 425 DIAMETERS.

Magnetite replaced by hematite. J/, magnetite; H, hematite; G, gangue.

—s a a — ——