Abstract The measurement of anhysteretic remanent magnetization (ARM) is an easy nondestructive means of evaluating many important rock properties. This involves applying an alternating magnetic field (AF) along with a direct biasing field (DF) to magnetize rock samples. Various techniques employing ARM have been widely used with notable success to help solve problems in tectonics, volcanology, sedimentology, environmental and paleoclimate studies and to better understand geomagnetic field behavior. Often, however, too little attention is paid to the effects of switching field angular dependence, which has important influence on the coercivity and angular distributions of grains that actually carry the ARM. As a result, commonplace methods of ARM measurement are not ideally designed for their intended purposes. For example, differentiation of a progressive ARM acquisition or turning on the direct field within a narrow AF window (i.e. partial ARM) are unable to isolate the ARM contribution from a specified coercivity grain fraction. Instead, the optimal method of measuring ARM in a targeted coercivity grain fraction is to differentiate a progressive tumble demagnetization of a total ARM generated with a peak AF high enough to fully activate the coercivity range of interest. Ignoring the activation property can lead to overestimation of relative paleointensity, underestimation of high coercivity grain concentrations, amplification of ARM anisotropy (e.g. error in natural remanence corrections), and unwanted mixing of anisotropy fabric components held in separate coercivity grain fractions.

中文翻译：

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无磁滞剩磁应用切换场角度依赖性的后果

摘要 无磁滞剩磁（ARM）的测量是评估许多重要岩石特性的一种简单的无损手段。这涉及应用交变磁场 (AF) 和直​​接偏置场 (DF) 来磁化岩石样品。使用 ARM 的各种技术已被广泛使用并取得显著成功，以帮助解决构造学、火山学、沉积学、环境和古气候研究中的问题，并更好地了解地磁场行为。然而，通常很少关注开关场角度依赖性的影响，这对实际携带 ARM 的晶粒的矫顽力和角度分布具有重要影响。因此，常见的 ARM 测量方法并未针对其预期目的进行理想的设计。例如，渐进式 ARM 采集的区分或在狭窄的 AF 窗口（即部分 ARM）内打开直接场无法将 ARM 贡献与指定的矫顽力颗粒分数隔离开来。相反，在目标矫顽力颗粒分数中测量 ARM 的最佳方法是区分具有足够高的峰值 AF 生成的总 ARM 的渐进式滚转退磁，以完全激活感兴趣的矫顽力范围。忽略活化特性会导致相对古强度的高估、高矫顽力颗粒浓度的低估、ARM 各向异性的放大（例如自然剩磁校正中的误差）以及保持在单独的矫顽力颗粒部分中的各向异性织物成分的不需要的混合。