Carbonatites are the most ridiculous type of igneous roks in the world : mostly made of igneous carbonates. In the ca. 1.2 Ga Phalaborwa pipe (NE South Africa), they occur in association with some other alkaline rocks, for which I do not have photos yet.

The carbonatite itself contains mostly carbonates but also garnet, phlogopite and possibly feldspathoids.

The complex is mined by no less than three companies, PMC (Phalaborwa Mining Co.) mines the copper-bearing carbonatites in the core of the pipe, and digged the big hole that is quite prominent in the landscape. Foskor mines phosphorus, from apatite that occurs in apatite, in the pyroxenites around the pipe (so they are effectively processing the "refuse" of PMC mine !). And vermiculite (a phyllosilicate with useful thermal properties) is mined, from phlogopite pegmatites.

Post-Scriptum :

If some happy Maties happened to google around searching for info on Phalaborwa carbonatites, because of a certain IgPet lecturer, and arrived on this site, please be advised : a personal website/blog is not to be regarded as an academic reference. If you consider using material from this page (say, for an assignment ?), contact the author — should not be too difficult.

Téléchargez cet article au format pdf :