许多地质数据组都是由较少的几个端元组分混合而成的,一般的解释手段是把一组数据分解成不同的组分。例如,古生物学家把化石必须分成几个环境族,岩石学家必须区分组成熔岩流系列的母岩浆,沉积学家一定要判明采集区沉积物样品中重矿物的不同源区。在纯的端元组分采集不到时,当然需要一种特殊 Many geologic data sets are made up of a mixture of fewer end units, and the general explanation is to break up a set of data into different components. For example, paleontologists divided fossils into several environ- mental families. Petrologists had to distinguish the parent magma that formed the series of lava flows. Sediologists must identify different source areas of heavy minerals in sediment samples collected in the area. Needless to say, there is of course a special nature when pure end-cell components can not be collected