Hydrocarbon alteration and adsorption can influence geochemical field of elements through enhancing dissolubility of fluids

changing redox conditions and pH values of media and impacting wettability of soil particles. The geochemical field of elements is closely related with the energy minerals in Ordos basin. The superposition zones of low background of iron group and chalcophile elements are the major lodging points of coal and natural gas. The transitional zones between low backgrounds of W Mo group elements and iron group and chalcophile elements are the favorable enriched zones of uranium deposits. The low background areas of W Mo group elements are the prospective enriched zones of hydrocarbons and coals. Large scale and high ranked low or high backgrounds of elements are generally correlated with large and rich deposits. The geochemical field of surface elements in Ordos basin and the surrounding areas can be divided into 4 zones

of which zoneⅠis enriched with oil

natural gas and coal

zoneⅡis the enriched zone of natural gas

coal and uranium

zone Ⅲ is the coexisting zone of oil and coal

and zone Ⅳ is the enriched zone of polymetralic and noble metallic ore and uranium deposits.