Chemistry, Morphology and Origin of Magmatic-Reaction Chromite Stringers Associated with Anorthosite in the Upper Critical Zone at Winnaarshoek, Eastern Limb of the Bushveld Complex

Buy Roger N. Scoon1 and Gelu Costin.

The occurrence of numerous chromitite layers within the Rustenburg Layered Suite of the Bushveld Complex, South Africa, has been widely cited in models to explain the origin of the igneous layering. Most hypotheses are based around the principle of episodic replenishment of the magma chamber. Chromitite layers occur in both the Lower Critical Zone (LCZ), which is wholly ultramafic, and the Upper Critical Zone (UCZ), where they are part of repetitive units that include pyroxenite (+/-minor harzburgite), norite and anorthosite.