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最近的实验研究已表明,消除含磁铁矿岩石里的粘滞剩磁(VRM)所需要的温度,比标准的Neel单畴理论所预计的要高得多。被一些人用来解释增强的热稳定性的Walton时间-温度方程,准确地叙述了在不同温度下获得的VRM强度,而不是描述以前获得的VRM的解阻。我们证明了用于所有以前公式里的低场近似(LFA),对处于地磁场里磁铁矿的集合体是无效的。这个先前的公式预计了同等的VRM的获得和衰减速度对于在集合体里的更大颗粒,中等场近似(MFA)预计了VRM更快的获取和在衰减方面更高的热稳定性。传统的理论的确适用于红层的获取及衰减试验,因为LFA对赤铁矿是有效的。
Recent experimental studies have shown that the temperature required to eliminate viscous remanence (VRM) in magnetite-bearing rocks is much higher than predicted by the standard Neel single-domain theory. The Walton time-temperature equation, used by some to explain the enhanced thermal stability, accurately describes the VRM intensity obtained at different temperatures, rather than describing the previously obtained VRM de-blocking. We prove that the low field approximation (LFA) used in all of the previous formulas is not valid for the assemblage of magnetites in the geomagnetic field. This previous equation predicts the acquisition and decay rates of the equivalent VRMs For larger particles in the aggregate, the medium field approximation (MFA) predicts faster VRM acquisition and higher thermal stability in attenuation. The traditional theory is indeed suitable for red layer acquisition and attenuation experiments, because LFA is effective for hematite.