Rare-earth element contents of Kizildag and Kemiklitepe bauxite deposits, central Tauride, Turkey: implications for REE potential in bauxites

Abstract

The Kizildag and the Kemiklitepe bauxite deposits are located in the Bolkardag bauxite province, which is the second most important Turkish province for bauxite production after Seydisehir-Akseki. The bauxite deposits in Bolkardag province resulted from the lateritization of Lower-Upper Triassic shales. In the Bolkardag region protolith, saprolite and bauxite transition processes are well observed and permitted to characterized the behaviour of the elements during bauxitization. The bauxite in this region consists of diaspore, hematite, goethite, anatase and magnetite, which developed between the Upper Triassic and Middle Jurassic (Aalenian). While the REE contents from protolith to bauxite decreased from the Kizildag bauxite (average 1017, 883 and 750 ppm for protolith, saprolite and bauxite, respectively), it increases in the Kemiklitepe bauxite (average 436, 424 and 1043 ppm) during bauxitization. This can be explained by the fact that the REE-bearing minerals have weathered and REE have leached during bauxitization in Kizildag, while in the Kemiklitepe deposit, the REE-bearing resistant minerals in the protolith were transported to bauxite. The Kizildag protolith resembles the Chinese clays mined for REE with respect to its mineralogy and REE content, and could be a potential REE source.