Fundamental rock magnetic studies on single-domain particles, impressed magnetic anisotropy, and the application of rock magnetic techniques to petrophysics

单畴粒子的基础岩石磁学研究、外加磁各向异性以及岩石磁学技术在岩石物理学中的应用

• 批准号: 386245-2010
• 负责人: Potter, David
• 金额: $ 3.13万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=463706
• 关键词: Fundamental; rock; magnetic; studies; single

This program will study some fundamental and applied aspects of rock magnetism. Important information concerning the intensity and direction of the Earth's ancient magnetic field (paleomagnetism) is carried by small stable single-domain (SD) particles in rocks. The information they carry is locked-in when the rock is formed, and can remain stable over millions of years. This program will study the fundamental properties of SD particles, and extend our recent discoveries. In particular, we have recently demonstrated that there is a range of stable positions in which the magnetic moment can lie in SD particles. Understanding this important feature potentially allows improved computations of the ancient field direction and intensity to be made from anisotropic rocks. This potentially allows useful paleomagnetic data to be obtained from a wider range of samples than are generally currently studied (including older samples, which are often more anisotropic and disregarded due to difficulties in estimating reliable paleomagnetic data from them). We will also be examining the properties of particles slightly larger than SD size, and quantifying the conditions under which these particles can transform into a metastable SD state. This is extremely important since it may help to explain why a significant fraction of the natural remanent magnetization (NRM) in rocks appears to reside in these slightly larger particles.

本课程将研究岩石磁学的一些基础和应用方面。关于地球古代磁场（古地磁）的强度和方向的重要信息是由岩石中的小而稳定的单畴（SD）粒子携带的。它们携带的信息在岩石形成时就被锁定了，并且可以在数百万年内保持稳定。这个项目将研究SD粒子的基本性质，并扩展我们最近的发现。特别是，我们最近已经证明，有一个稳定的位置范围内的磁矩可以躺在SD粒子。了解这一重要特征可能会改进计算的古磁场方向和强度，从各向异性岩石。这可能允许从比目前通常研究的更广泛的样本中获得有用的古地磁数据（包括较老的样本，这些样本通常更具各向异性，并且由于难以从它们中估计可靠的古地磁数据而被忽略）。我们还将研究略大于SD尺寸的粒子的性质，并量化这些粒子可以转化为亚稳态SD状态的条件。这是非常重要的，因为它可能有助于解释为什么岩石中的天然剩磁（NRM）的很大一部分似乎存在于这些稍大的颗粒中。