The site and surrounding area are underlain by the Pyramid Formation of the Rustenburg Layered Suite (RLS), on the western limb of the Bushveld Igneous Complex. The suite of mafic sills, which intruded the basal rocks of the Transvaal Supergroup, comprises rocks that range from norites, pyroxenite, harzburgite, gabbronorite, magnetite and olivine-magnetite rich gabbronorite, anorthosite and olivine-apatite rich gabbronorite.

The most prominent feature from the RLS is the distinct layering in the different rock types due to differentiation of magma that Brink (1989) describes as pseudo-stratification. The originally placed layers of the Bushveld Complex rocks dips centripetally at between 100 and 200, which is attributed to the effect of the crustal flexure in response to the load of the RLS and associated granites.

The rock-forming minerals of the Merensky Reef comprise approximately equal amounts of dark iron magnesium silicate minerals and lighter calcium-aluminium-sodium silicate minerals (called a feldspathic pyroxenite) under- and overlain by thin (5 to 15 mm) often discontinuous layers of chrornite concentrations. The total thickness of this package is generally less than 30 cm. This zone, commonly known as the Merensky pegmatoid, contains the base metal sulfide grains and associated platinum group minerals. The Merensky Reef has been traced for 300 km around the entire outcrop of the eastern and western limbs of the Bushveld Complex, and to depth ........

Generally, underground longwall or scattered mining methods are used to mine the Merensky reef and the UG2. Most orebodies at SBPM occur as narrow tabular orebodies that are continuous along dip and strike. SBPM utilises various types of underground mining methods, that vary in the mining direction, and the method of accessing the orebody, but which in essence are all varieties of narrow tabular stoping:
1. Mining Methods of UG2 reef;
- Conventional scattered breast;
- Longwall;
- Down-dip and up-dip mining;
- Hybrid Trackless mining (i.e., trackless on reef drives with conventional panels in between).
2. Mining Method of Merensky reef
- Down-dip and up-dip;
- Scattered.

The Merensky reef is mined to an average depth of 1,400 m and it is intended that this depth will be extended to a depth of 2,000 m for down-dip. The UG2 reef is currently mined to an average depth of about 1,700 m.

At the current 4B opencast operation, owing to multiple reefs being extracted from the pit (Merensky, Tarentaal and Pseudo Merensky) at dips that vary between 18 and 40 degrees, the box cut method has been varied, such that it involves pavilions or benches that are opened from a single access incline, followed by roll over mining as soon as sufficient mined out space in the pit became available.

The 4B opencast operation is scheduled to be depleted in 2022.

The New pit is the continuation of the 4B opencast operation.

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