Bauxite deposits are classified into three main types based on their geological formation: lateritic, karst, and Tikhvin (sometimes called terrane or detrital). Lateritic types dominate globally at about 88% of reserves, while karst accounts for roughly 12%.
Lateritic Bauxite :
These form through intense surficial weathering (lateritization) of aluminosilicate rocks like basalt, granite, or gneiss in tropical climates with good drainage. They appear as blanket-like layers on plateaus. Examples include deposits in Australia (Weipa), Guinea, Brazil, India (Odisha's East Coast and Eastern Ghats), and Indonesia.
Karst Bauxite :
These develop in depressions or eroded surfaces on carbonate rocks (limestone, dolomite) via residual and transported aluminous materials, often in wet tropical areas. They feature pisolitic, nodular, or earthy textures and are richer in rare earths. Examples occur in Europe (Greece, Hungary, France), the Caribbean (Jamaica), China, and Russia.
Tikhvin (Terrane) Bauxite :
These are detrital deposits overlying eroded aluminosilicate rocks, resulting from mechanical transport and redeposition rather than in-situ weathering. They form undulating ore bodies and are less common. Examples are found in regions like Russia's Tikhvin deposit and some Central Indian pockets.
Description provided by indian stalwart global sourcing company.