Abstract:
Very limited studies have been conducted on titaniferous-magnetite exsolution textures and
the conditions needed for the formation of these textures. Published research surrounding
the exsolution textures consider only a particular element of the oxide, or a specific
condition. The Upper Zone of the Rustenburg Layered Suite in the Bushveld Igneous
Complex boasts 25 magnetite layers. The 21st layer counted from the Main Magnetite layer
is called Layer 21, which is the uppermost titaniferous-magnetite layer in the Upper Zone.
Uncommon exsolution textures in the titaniferous-magnetite grains were studied in order to
gain a greater understanding of the formation of oxide exsolution textures. The exsolution
texture presents itself as a three-dimensional framework of ulvöspinel-rich lamellae together
with magnetite prisms. This is called a cloth texture exsolution. The data collected for this
investigation included Scanning Electron Microscope (SEM) images, elemental weight
percentage data, and SEM line scans. Previous studies do not show exsolution textures that
are exactly similar to the exsolution textures seen in Layer 21, although the same basic type
of microtexture can be seen. This indicates that conditions such as temperature, pressure,
and oxygen fugacity, as well as the bulk mineral chemistry, plays a large role in the formation
of the exsolution texture. A rough model has been provided that considers all of the
information collected in previous studies in order to start the development of a complete
model. Another model has been provided explaining the physical appearance of the cloth
texture exsolution. The exsolution textures need to be investigated on a three-dimensional
basis in order to develop a more accurate understanding of why the titaniferous-magnetite
exsolution textures are different from location to location.
