非磁滞剩磁(ARM)及其在地学中的应用

Anhysteretic remanent magnetization(ARM) and its application to geoscience

非磁滞剩磁(ARM)是实验室中人为产生的剩磁之一,其获得过程是在一个幅度逐渐降低的交变场中,同时叠加上一个很小的直流场所获得的剩磁.非磁滞剩磁作为岩石磁学重要的剩磁参数之一,已广泛地应用于古气候环境演化及古磁场相对强度变化的研究中.同其他岩石磁学参数相似,非磁滞剩磁具有较为复杂的性质并受多种因素影响.因此,正确认识非磁滞剩磁的性质对于解决复杂的地学问题至关重要.本文从物理基础出发,系统地论述了非磁滞剩磁的特征及其主要的影响因素(包括颗粒的粒径、磁相互作用、交变退磁场幅值的衰减率等),并对比了其与热剩磁(TRM)之间的异同。最后,简要介绍了非磁滞剩磁在相对古强度和海陆古气候变化中的应用.

The Anhysteretic remanent magnetization（ARM）,a magnetization obtained in an alternating magnetic field that is gradually reduced to zero with a superimposed biased direct magnetic field,has been widely used for paleoclimatic and paleointensity studies.Similar to other parameters of Rock Magnetism,ARM possesses complex characteristics,and is affected by many factors.Thus,ambiguities are inevitable for the interpretation of this magnetic proxy.This review systematically discussed the special characteristics and major factors that affect ARM,including the grain size of magnetic minerals,interaction field,the alternating field decay rate and so on.In addition,ARM is also compared with the thermoremanent magnetization（TRM）.Finally applications of anhysteretic remanent magnetization to geoscience are outlined.