Published on: Dec 8, 2016
By Kylie Williams
Certain minerals, such as magnetite, are valued for their role as magnetic time capsules, locking-in the direction and intensity of the Earth’s magnetism at the time they were formed. This magnetic memory, called remanence, is a useful tool for dating rocks and rock sequences, but can be misleading for geophysicists modelling magnetic and gravity data.
In 2010, Ivanhoe Mines requested the expertise of Barry de Wet and Nick Williams, both geophysicists with Ivanhoe Australia at the time, to help overcome this remanence problem at their flagship Platreef Project in the Bushveld Igneous Complex (BIC), 280 kilometres northeast of Johannesburg in South Africa.
The Platreef, a high-grade reef of platinum group element (PGE), nickel, copper, and gold mineralization, occurs just below a regional contact within the BIC that can be traced more than 30 kilometres along strike. Ivanhoe geologists correlate the reef with the famous Merensky and UG2 PGE reefs which account for 60% of the world’s annual PGE production.
Read the full article: Earth Explorer, Geosoft.com