Freda Rebecca Gold Mine (FRGM), located 90km northeast of Harare in Zimbabwe and lies on the central axis of the synclinal Mazowe-Bindura Greenstone belt.
The geology of the area around FRGM is characterised by the Shamvaian sediments, diorite and granodiorite. Dolerite dykes cut through the three rock types.
The FRGM orebodies are largely hosted by the Prince of Wales diorite and the Bindura granodiorite, with limited transgressions into the metasediments.
The mineralisation is hosted within two major shear envelopes: the footwall/curvilinear Freda-Promoter which strikes from north-east through to east west and dips at 0 to 25° to the south; and the Rebecca which strikes northwest and dips at 35°.
Individual shears are variable in width and these two systems merge to the southwest at depth flattening at around 850m elevation and extending into the metasediments.
The shear system is characterized by a set of anastomosing shears separated by relatively undeformed rock units.
At FRGM there are two styles of sulphide mineralisation: older disseminated, pervasive sulphides occurring throughout the sediments, diorite and granodiorite, which vary in intensity and grade; and younger mineralisation restricted to shear zones and associated with higher gold grades.
In both types of mineralisation, higher grades are associated with fine-grained sulphides.
Sulphides include arsenopyrite, pyrite, pyrrhotite and chalcopyrite.
Mineralisation is characterised by patchy micaceous chloritic alteration with some silicification and to a lesser degree, carbonatization.
Quartz veins generally do not carry gold values but may contain minor amounts of sulphide.
Payable gold mineralisation is not visually distinct, so assaying is required to outline the ore zones.
Mining Operations
FRGM efficiently extracts gold from its deposits through a combination of opencast and underground operations.
The mine has been a consistent low-grade, high-volume producer, carving its niche in the mining landscape.
With a 20-year production history, FRGM has been a stalwart in the gold mining sector.
The mine’s strategic location within the Shamva/Harare Greenstone Belt has played a pivotal role in its success.
Notably, FRGM boasts an impressive monthly gold production of 260 kilograms, solidifying its position as a major contributor to the gold production landscape.