Experimental Evaluation of Remanence Carriers Using the Microcoercivity‐Unblocking Temperature Diagram
Experimental Evaluation of Remanence Carriers Using the Microcoercivity‐Unblocking Temperature Diagram
复制标题
使用微矫顽力-解锁温度图对剩磁载流子进行实验评估
DOI：
10.1029/2019gc008534
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Tsunakawa Hideo
中科院分区：
文献类型：
--
作者：
Sato Masahiko;Terada Takuma;Mochizuki Nobutatsu;Tsunakawa Hideo
对记录介质中剩磁载体的了解对于获得可靠的古地磁数据至关重要。本文报道了一种利用磁滞剩余磁化强度(ARM)谱确定天然岩石样品中剩磁载流子的新技术。通过系统的ARM结合热退磁和交变磁场退磁处理的逐级退磁实验，并在Hc-TUB平面上计算ARM强度的变化(HC-TUB图)，确定了ARM载体的分布。对三个玄武岩和两个焊接凝灰岩的样品进行了分析。结合Hc-TUB图和ARM矫顽力谱的变化，可以确定实验室加热过程中由于热蚀变而导致的磁性矿物的减少和增加。从实验样品中，ARM载体成分被鉴定为原始的，而不是由于热蚀变而产生的。对于Izu-Oshima 1986 A熔岩流(1986La)样品，从Hc-TUB图上证实，高HC组分可以通过逐步交变退磁处理而不是逐步热退磁处理来分离。在伊豆-大岛1986年的熔岩流样品上也进行了古强度实验。三个古强度估算中有两个大于预期场强，表明某种岩石磁性影响了古强度估算。伊豆-大岛1986 A熔岩流样品的Hc-TUB图表明，古强度估算的差异可能是由于高温氧化状态的不同程度造成的。
Knowledge of remanence carriers in recording media is crucial for obtaining reliable paleomagnetic data. In this paper, we report a newly developed technique to determine remanence carriers in natural rock samples that uses anhysteretic remanent magnetization (ARM) spectra in the microcoercivity (hc) and unblocking temperature (TUB) planes. The distribution of ARM carriers was determined via systematic stepwise demagnetization experiments of ARM combining thermal demagnetization and alternating field demagnetization treatments and calculating the change in ARM intensity on thehc‐TUBplane (hc‐TUBdiagram). Samples from three basaltic lavas and two welded tuffs were analyzed. Combining thehc‐TUBdiagram with the change in ARM coercivity spectra, both decreases and increases in magnetic minerals due to the thermal alteration during laboratory heating could be identified. From experimental samples, ARM carrier components were identified as being original rather than produced as a result of thermal alteration. In the case of the Izu‐Oshima 1986 A lava flow (1986La) sample, it was confirmed from thehc‐TUBdiagram that high‐hccomponents can be separated using stepwise alternating field demagnetization treatment but not stepwise thermal demagnetization treatment. Paleointensity experiments were also conducted on Izu‐Oshima 1986 A lava flow samples. Two of the three paleointensity estimates were greater than the expected field intensity, suggesting a certain rock‐magnetic property that affects the paleointensity estimation. Thehc‐TUBdiagrams of the Izu‐Oshima 1986 A lava flow samples suggest that the differences in the paleointensity estimates were likely caused by different degrees of the high‐temperature oxidation state.
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影响因子：
2.8
作者：
Y. Yamamoto;H. Tsunakawa;H. Shibuya
通讯作者：
Y. Yamamoto;H. Tsunakawa;H. Shibuya
影响因子：
5.3
作者：
Fabian, K
通讯作者：
Fabian, K
影响因子：
2.8
作者：
T. Rolph;J. Shaw
通讯作者：
T. Rolph;J. Shaw
DOI：
--
发表时间：
2000
期刊：
影响因子：
--
作者：
K. Fabian
通讯作者：
K. Fabian