在北美的Basin和Range成矿省,大片的基岩被运积物覆盖。在这些地区,利用土壤的选择性化学分析,可测定进入覆盖层某一痕量元素的量值,而并非测定覆盖层样品中该元素的总量。这一技术可用来探测矿化基岩。在干旱气候条件下,深部硫化矿物释放出来的痕量元素因毛细管作用或挥发分的扩散而向上迁移至覆盖层。这些元素可进入上覆土壤中矿物颗粒表面的氧化锰和氧化铁包层内。 In the Basin and Range metallogenic provinces of North America, massive bedrock is covered by sediments. In these areas, the selective chemical analysis of soils can be used to measure the amount of a trace element entering the overburden rather than determining the total amount of the element in the overburden sample. This technique can be used to detect mineralized bedrock. Under arid climatic conditions, trace elements released from deep sulphide minerals migrate up to the overburden due to capillary action or the diffusion of volatiles. These elements can enter manganese oxide and iron oxide coatings on the surface of mineral particles in overlying soils.