岩石风化成土过程中元素均一化作用及机理:以大兴安岭北部火山岩区为例

Elemental homogenization during weathering and pedogenesis of volcanic rocks from North Da Hinggan Ling

对大兴安岭北部区域性中生代火山岩和残积土壤化学成分的研究结果表明,岩石风化成土过程中元素存在明显的均一化作用。元素含量高的岩石风化形成的土壤中元素含量相对降低,反之则相对增高,导致残积土壤中元素含量差异明显小于基岩。不同元素的均一化能力不同,在主元素中,Al2O3和SiO2的均一化能力相对较弱,微量元素的均一化能力普遍较强。元素的均一化能力受元素晶体化学性质、元素存在形式、矿物抗风化能力、气候、水动力条件及生物等因素影响。

Chemical compositions of regional volcanic rocks and residual soil in North Da Hinggan Ling are studied, and elemental homogenization is recognized during weathering and pedogenesis of the volcanic rocks. The element contents in soils from rocks with high element contents relatively reduce and those from rocks with low element contents relatively increases, which results in the reduction of the element content variance of soil compared with that of rock. The ability to homogenize is very different among the elements. Homogenization of Al2O3 and SiO2 is relatively weak, and that of trace elements is generally very strong. Intensity of elemental homogenization depends on the crystal chemical property of element, existing state of element, mineral stability resistance to weathering, climate, hydrodynamic condition and biological activity and so on.