Grootboom Farm, Fetakgomo Tubatse Local Municipality, Sekhukhune District Municipality, Limpopo, South Africai

Regional Level Types
Grootboom Farm	Mine
Fetakgomo Tubatse Local Municipality	Municipality
Sekhukhune District Municipality	Municipality
Limpopo	Province
South Africa	Country

Farm 336KT situated next to Annex Grootboom Farm 335KT and 10 km north-northeast of Steelpoort. In the early days of the 'platinum rush' prospectors exposed the Merensky Reef as can be seen in old shafts and adits on a high hill on this farm. In 1955 the Lavino Chrome mine was established. The Farm and mine was sold to 'Anglovaal Limited' who in turn sold the chrome mineral rights and mine to Samancor.

In the Grootboom Hill area the Upper Group Chromite Layers and the Merensky Reef are developed. The general strike is north-northeast with layering dipping westward at 10° to 15°. Close to the Transvaal floor the Bushveld Complex has been folded into a series of domes and basins. The Grootboom Hill deposit represents a basinal structure preserved in a prominent hill as an erosional outlier to the main UG2 subcrop. Only a small amount of Merensky Reef is preserved towards the top of the Grootboom Hill.

Grootboom Valley is to the northwest of Grootboom Hill and on the north-western or downthrown side of the Steelpoort fault. The UG2 Chromitite Layer occurs at depths ranging from 25m to 450m below surface, strike is northwest with dips approximately 12° southwest. Outcrop in the Grootboom Valley is sparse as the area is generally covered by fertile transported soil and alluvial gravel terraces of the Steelpoort River.

The Grootboom Project has three distinct zones of mineralization: Grootboom Hill, Grootboom Valley, and the Grootboom tailings project. The UG2 Chromitite Layer on the Grootboom Hill occurs as a single massive seam averaging 120cm in thickness. Thin chromitite stringers are present in the pegmatoidal pyroxenite immediately above the
UG2 with further pegmatoidal pyroxenite with minor chromitite stringers forming the footwall to the UG2.

The Merensky Reef outcrops around Grootboom Hill and comprises a medium grained pyroxenite (two metres to eight metres thick) that seldom has a pegmatoidal component and which does not have well developed upper and lower chromitite stringers. PGM mineralization is concentrated primarily in the top one metre of the pyroxenite. The Merensky Reef has a hanging wall of norite and mottled anorthosite and a leuconoritic to anorthositic footwall.

On Grootboom Valley, the UG2 Chromitite Layer consists of a main chromitite seam which, averages 85cm. The main chromitite seam is often split by thin (less than 10cm) anorthositic and pyroxenitic partings. A thin (one millimetre to two millimetre) leader chromitite is sometimes developed roughly 5mm above the main UG2 Chromitite Layer and is separated from the main seam by pyroxenite. The footwall to the UG2 Chromitite Layer is a pegmatoidal pyroxenite containing discrete coarse grained olivine that contains disseminated chromite and chromitite bands. Grades quoted for the Grootboom Valley are for chromitite only and do not include mineralization in the footwall, which can be extensive
in places.

A number of companies have previously undertaken chrome mining on Grootboom and Annex Grootboom. In the washing and concentrating of the final saleable products, these mines produced large volumes of material now contained within a tailings dump on Grootboom. These tailings have been found to contain low grades of PGMs and numerous metallurgical test reports suggest that recoveries of up to 70% may be possible. (Source: TSXProspectus.pdf)

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