Experimental Study of the Interaction between Hemoilmenite and Kimberlite Melt at a Pressure of 2 GPa

摘要

The Massadou kimberlite field [3] located in Guinea is characterized by a high concentration of ferrimagnetic (at room temperature) ilmenite in kimberlite with the total content up to 90% in individual bodies (dykes) [10]. Detailed study of these ilmenites demonstrated the presence of a clear rim with the average thickness varying from body to body. The core parts of ilmenites are enriched in the hematite component and depleted in Mg, Ti, and Cr, whereas the rim is represented by picroilmenite paramagnetic at room temperature, which is typical for kimberlite; this mineral is enriched in Mg, Ti, and Cr and depleted in Al and Fe~(3+) [10].