In the pre-Quaternary geological history, as long as there were hiatuses caused by epeirogenic movements there were favorable conditions for forming the old weathered crust solid ores and petroleum. Bed rocks with different chemical properties of the bed rocks may be weathered to form differents old weathered crust solid ores, such as rich iron ore, bauxite, nickel ore, rich manganese ore, gold ore, cobalt ore, clay, rare metla ore and rare-earth metal ore. The mechanisms of mineralizations, whether at present or in ancient times, are more or less the same. The mineralization of the old weathered crust solid mineral deposits generally occurred in ancient tropical zones or subtropical zones and in some cases occurred as a result of biochemical weathering. Study shows that the mineralization due to biochemical weathering mainly occurred in subtropical zones and less commonly in tropical zones.
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