A Preisach method for estimating absolute paleofield intensity under the constraint of using only isothermal measurements: 1. Theoretical framework
A Preisach method for estimating absolute paleofield intensity under the constraint of using only isothermal measurements: 1. Theoretical framework
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DOI：
10.1029/2010jb007843
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发表时间：
2011-04
影响因子：
--
通讯作者：
A. Muxworthy;D. Heslop
中科院分区：
文献类型：
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作者：
A. Muxworthy;D. Heslop
[1]描述了一种新的非加热法测定古磁场绝对强度(古强度)的理论框架。该方法基于热激活的Preisach模型，该模型用于相互作用的、具有单轴各向异性的随机取向的单畴颗粒。该模型包括了以前的非加热古强度方法所不具备的理论特征，例如，它考虑了静磁相互作用，允许可变的冷却速度，并且可以识别、隔离和拒绝不稳定的剩磁载流子，即多域和超顺磁性贡献。根据岩石样品的一阶反转曲线分布中包含的信息，得到了输入Preisach分布，根据该分布可以模拟给定岩石样品的热剩磁(TRM)的获取。古强度估算是通过比较样品天然剩磁的交变退磁谱和模拟的TRM来确定的。在随附的论文中，该协议使用一套历史样本进行了严格的测试。
[1] The theoretical framework for a new nonheating method of determining absolute ancient magnetic field intensities (paleointensities) is described. The approach is based on a thermally activated Preisach model for interacting, randomly orientated single-domain grains with uniaxial anisotropy. The model includes theoretical features not accommodated by previous nonheating paleointensity methods; for example, it includes magnetostatic interactions, allows for variable cooling rates, and can identify, isolate, and reject unstable remanence carriers, i.e., multidomain and superparamagnetic contributions. The input Preisach distribution from which the acquisition of a thermal remanent magnetization (TRM) of a given rock sample can be simulated is obtained from information contained in the sample's first-order reversal curve distribution. The paleointensity estimate is determined by comparing the alternating field demagnetization spectrum of the sample's natural remanent magnetization and its simulated TRM. In the companion paper, the protocol is rigorously tested using a suite of historical samples.