The Merensky and UG2 Reefs are separated by a sequence of mostly anorthositic and noritic layered units of some 400m in combined thickness. Both the Merensky and UG2 Reefs are present but only the UG2 is currently exploited. The geological succession is broadly similar to that of the western limb. The UG2 Reef is defined as a main chromitite layer, with most of the mineralisation confined to this unit, followed by a poorly mineralised pegmatoidal footwall. The Merensky Reef is the upper portion of a pyroxenite layer, with a chromitite stringer close to the hanging wall contact. Mineralisation peaks over the chromitite stringer and decreases into the hangingwall and footwall. The average 6E metal ratios show the distinct differences between the Merensky and UG2 Reefs, in particular the high proportion of palladium associated with the UG2 at Marula and also the relative high proportion of rhodium in the UG2 Reef.

Both mineralised horizons sub-outcrop on the Marula mining rights area and dip in a west-southwest direction at 12° to 14°. The reefs are relatively undisturbed by faults and dykes with one major dolerite dyke traversing the mining area. Potholes represent the majority of the geological losses encountered underground, while a small dunite pipe also disrupts the reef horizons. These geological features are accounted for in the Mineral Resource and Mineral Reserve Statements as geological losses.

Both reefs strike north-north-west to south-south-east, with a vertical thickness of approximately 400 m between the Reefs. The Merensky Reef is located about 650 m below the surface with the UG2 Reef approximately 400 m deeper than the Merensky Reef. The Merensky Reefs occurs near the top of the Upper Critical Zone in a sequence of rocks knows as the Merensky Cycle.

The Merensky Pyroxenite Unit comprises the top of the Merensky Upper Pyroxenite (MPU), the Merensky Chromitite Marker (MRC), the Merensky Lower Pyroxenite, the Merensky Lower Chromitite (MLC), and the Merensky Pegmatoid (MPG). A third chromitite stringer, the Merensky Pegmatoid Chromitite, is intermittently developed at the base of the pegmatoid. Sulphide (and PGE) mineralisation is associated mainly with the upper (MRC) and lower (MLC) chromitite stringers and the pyroxenite between these stringers. The PGE mineralisation is concentrated mainly from the Merensky Chromitite Marker (MRC) down towards the middle of the Merensky Lower Pyroxenite (MLP).

Marula Mine has two decline shaft systems exploiting the UG2 Reef. At Driekop Shaft, a hybrid mining method is used, while at Clapham Shaft, both hybrid and conventional mining methods are being used. All main development is undertaken on-reef for the two hybrid sections, and the stoping is carried out through conventional single-sided breast mining from a centre gully. Panel face lengths are approximately 16m to 26m, with panels separated by 6m x 4m grid pillars with 2m ventilation holings. The stoping width averages 125cm. The footwall drives are developed on strike approximately 25m below the reef horizon, with cross-cut breakaways about 220m apart for the conventional operation. This development is undertaken with drill rigs and dump trucks. Stope face drilling takes place with hand-held pneumatic rock drills with airlegs.

Removal and storage of ore
The ore from the current UG2 operations is transported via a conveyor belt to the run-ofmine silo located at each shaft (1 500 ton capacity). Under normal operating conditions, the ore is conveyed from the silo to the primary crusher. In the event that the processing plant is offline, the ore is conveyed to a 20 000 tonne emergency run- of-mine stockpile area located near to the primary crusher.

Removal and storage of waste rock
Waste conveyed from underground is deposited on the designated waste rock dump (WRD) areas located at the Clapham and Driekop Shaft Complexes.

There is currently one mineral processing plant at the mine, namely the UG2 Concentrator Plant used for processing UG2 Reef mined from the Driekop and Clapham shafts.

In general terms, the processing activities at Marula comprise; crushing, milling, screening, floatation and tailing disposal.

Crushing, screening and hauling
The ore is processed at the UG2 Concentrator Plant at an average rate of 162 500 tpm. Under normal operating conditions, run-of-mine from the silos is fed via a conveyor to a primary crusher located at each shaft. If ore has been stockpiled on the emergency stockpile, then ore from the stockpile is loaded into the primary crusher via a front-end loader. Crushed ore is then conveyed from the primary crusher to two 10 000 ton silos located at the plant.

Concentrator Plant
The plant has a MF1 (mill-float) configuration and was designed to treat 200 000 tonnes run of mine per month. The plant occupies an area of approximately 4 ........