Ores and rocks specimens, Cuiaba deposit. Part II.

Ores and rocks specimens, Cuiaba deposit. Part II.

Tags: ankerite bif

Ores and rocks specimens, Cuiaba deposit. Part II.

Category: Ore

Deposit: Cuiaba

Description:

G. Replacement structures in hand specimen. sulfide layers (3) alternate with light quartz–carbonate layers (1) and dark quartz–carbonate layers (2). Locally, late quartz vein crosscuts the layers (4). Note the replacement of dark quartz–carbonate layer (1) by sulfides (3) (Canta Galo orebody, level 5).

H. Fully developed euhedral pyrite grain with inclusions of carbonate. Note that the replacement of ankerite takes place along grain boundaries (Canta Galo orebody, level 5).

I. Hand specimen of upper mafic metavolcanics showing sulfidation processes along discrete shear zones (Balancão Footwall orebody, level 5).

J. Quartz vein-type gold mineralization. Sulfides (with gold inclusions) occur along the mylonitic foliation and around quartz remobilization (Galinheiro Quartzo orebody, level 5).