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现代表土的磁学性质反映了物源、成土过程与气候环境之间的重要信息,对认识磁学参数在气候环境研究中的应用有重要意义。干旱区表土的磁学特性表现出极大的复杂性和差异性,为了理解不同气候和环境条件下表土磁学参数的特性、变化机制及控制因素,选择位于新疆北部阿勒泰地区不同景观带的表土样品作为研究对象。通过详细系统的环境磁学分析,并结合X衍射和粒度等方法,结果表明磁性矿物来源相对稳定,磁学性质主要由来自源区的粗颗粒软磁性矿物所主导,χ_(lf)(低频磁化率)和SIRM(饱和等温剩磁)与磁性颗粒表现出正相关的关系,磁性矿物浓度越大,磁畴颗粒越粗;反之,浓度越低,颗粒越细。磁性矿物的浓度和颗粒大小在不同景观带表现出一定的差异,荒漠带表土中磁性矿物的浓度较高,磁畴主要为粗颗粒的PSD(准单畴)+MD(多畴),而其他景观带(森林、灌丛、草原和湿地)矿物浓度明显较低,磁畴也相对较细。相比较,其他景观带表土受后期改造作用比荒漠区强,主要是由于在海拔升高到1300m之后,区域气候环境因素(如气温、降水以及蒸发)发生明显变化,导致强磁性矿物的破坏,土壤矿物浓度和粒径发生变化,磁性降低。成壤作用形成的SP(超顺磁畴)颗粒相对较少。
The magnetic property of modern topsoil reflects the important information between the source and the process of soil formation and the climate and environment, which is of great significance for understanding the application of the magnetic parameters in climate and environment research. In order to understand the characteristics, changing mechanism and control factors of surface soil magnetic parameters under different climatic and environmental conditions, the selection of the topsoil located in different landscape zones of Altay region in northern Xinjiang is of great complexity and diversity. Sample as the research object. The results show that the source of magnetic minerals is relatively stable and the magnetic properties are mainly dominated by the coarse-grained soft-magnetic minerals from the source region. Χ ~ (lf) (low-frequency magnetization Rate) and SIRM (saturated isothermal remanence) show a positive correlation with the magnetic particles. The larger the magnetic mineral concentration, the more coarse the magnetic domain particles. Conversely, the lower the concentration, the finer the particles. Concentrations of magnetic minerals and particle size show some differences in different landscape zones. The concentrations of magnetic minerals in the topsoil are higher, and the magnetic domains are mainly the coarse particles PSD (quasi-single domain) + MD (multidomain), while the other The landscapes (forests, shrublands, grasslands and wetlands) have significantly lower mineral concentrations and relatively smaller magnetic domains. Compared with other landscapes, the topsoil was more affected by the later remodeling than that in the desert, mainly due to the significant changes of regional climate and environmental factors (such as temperature, precipitation and evaporation) after the altitude was increased to 1300m, resulting in the destruction of ferromagnetic minerals, Soil mineral concentration and particle size change, magnetic reduction. Pedogenesis results in relatively few SP (superparamagnetic domains) particles.