Karnataka consists of four main types of geological formations – the "Archean complex" made up of Dharwad schists and granitic gneisses, the "Proterozoic" non-fossiliferous sedimentary formations of the Kaladgi and Bhima series, the "Deccan trappean and intertrappean deposits" and the tertiary and recent laterites and alluvial deposits. Significantly, about 60% of the state is composed of the "Archean complex" which consist of gneisses, granites and charnockite rocks. Laterite cappings that are found in many districts over the Deccan Traps were formed after the cessation of volcanic activity in the early tertiary period. Eleven groups of soil orders are found in Karnataka, viz. Entisols, Inceptisols, Mollisols, Spodosols, Alfisols, Ultisols, Oxisols, Aridisols, Vertisols, Andisols and Histosols. Depending on the agricultural capability of the soil, the soil types are divided into six types, "viz." red, lateritic, black, alluvio-colluvial, forest and coastal soils.