Great Panther Mining Limited, Tucano Gold Mine, Urucum gold deposit, Brasil. 

Foliation-parallel pyrrhotite mineralization - Urucum central open pit.

Foliation-parallel pyrrhotite mineralization

Golden Star Resources Ltd. Chujah gold deposit. Ghana.

On map.

Sheared graphitic sedimentary rocks of the Kumasi basin in contact with altered mafic volcanic lenses.

 

Graphitic sedimentary rocks with altered mafic volcanic lenses

Golden Star Resources Ltd. Bogoso gold deposit. Ghana.

On map.

Volcanic lense in the Bogoso North Pit steeply dipping to the West with sheared graphitic sedimentary package in the hanging wall. The lower picture illustrates the deformed nature of the quartz veins within the graphitic shear zone.

Mineralization style Bogoso gold deposit

Source:

Golden Star Resources Ltd

NI 43-101 Technical Report on Resources and Reserves, Golden Star Resources, Bogoso/Prestea Gold Mine, Ghana

Golden Star Resources Ltd. Prestea gold deposit. Ghana.

On map

Mineralized core intervals from four different Boreholes, from top to bottom, reef style mineralization (fault fill quartz veins) from Borehole GT-280S2 at a depth of 74.7 m. intersecting the West-Reef Structure, Borehole GT-287S1A at a depth of 130.7 m. intersecting the West-Reef Structure as well, Borehole UC30-270S-108 at a depth of 78.0 m intersecting the Main-Reef Structure, and at the bottom, a mineralized volcanic lens interval with visible gold and characterized by stockwork-like smoky quartz veins intersected in the footwall of the Main-Reef Structure by Borehole UC-270S-108 at a depth of 94.8 m.

Mineralized core from Presta gold deposit

Gold X Mining Corp. Sona Hill gold deposit. Guyana.

On map

Alteration is quartz-sericite-carbonate-chlorite alteration, both pervasive and as vein-related selvages. Carbonate minerals petrographically are described as predominantly dolomite, but calcite is also present. Mineralization is related to quartz veins, which tend to follow the rock foliations and the overall westerly dip. of the cataclastic deformation zone. Au mineralization is associate with quartz veins and minor sulfides (pyrite) and is hosted primarily in the intrusive rocks. Quartz veining, which is typically white crystalline quartz, and can be associated with feldspar, carbonate, tourmaline, sericite and chlorite, and minor sulfides (pyrite). Quartz veins can be from a few millimeters up to a meter or more in widths, but typically are in the 0.5 to 10 cm range. Rocks above the shear zone, which are the predominate host to mineralization, are petrographically described as porphyritic/micro-porphyritic/± equi-granular granodiorite to quartzdiorite intrusive rocks. The weathering or lateritic profile has resulted in the developed of saprolite at Sona Hill. Saprock is the transitional zone between saprolite and fresh rock, and forms as a gradational contact a few meters thick. Sap-rock and saprolite are generally thicker at Sona Hill, as the 25 to 30 m of topographic hill results in a greater depth to the water table. At Sona Hill, sap-rock and/or saprolite can be up to 60 m thick. Hill the weathering profile has produced a combination of saprolite and sap-rock, ranging from typical thicknesses of 30 m up to 60 m.

Sona Hill Core SOD 007 Saprolite

Sona Hill Saprolite