The Magaliesberg (historically also known as Macalisberg or as the Cashan Mountains) is a mountain range extending from Pretoria in the north of the Gauteng Province to a point south of Pilanesberg, in the North West Province, South Africa.The highest point of the Magaliesberg is reached at Nooitgedacht (1 852 metres).
The Magaliesberg Range has a very long geological history. Its quartzites, shales, chert and dolomite were deposited as sediments in an inland basin on top of the 3 billion year old Archaean Basement Complex. This process of sedimentation lasted for about 300 million years. About 2 billion years ago a massive upwelling of molten magma resulted in what is now known as the Bushveld Igneous Complex. The enormous weight of this intrusion depressed the sediments that lay beneath and tilted the sediments along the edges so that the broken scarps faced outward and upward, and the gentler dip slopes inward.
The range forms a natural barrier between the lower lying Bushveld to the north and the cooler Highveld to the south. The range receives rainfall in summer in the form of thunderstorms, with an average of 650 mm annually. In winter frost occurs frequently in the valleys on the southern side of the mountain, but almost never on the northern slopes.
Magaliesberg Biosphere Project:
The Magaliesberg Biosphere Initiative Group (with beginnings in 2006) is active in trying to get the Magaliesberg proclaimed a Biosphere by UNESCO.The Magaliesberg was proclaimed a Protected Natural Environment in 1977 however the protection applies only to the core area.