Recent advances in anisotropy of magnetic remanence: New software and practical examples

0379701 - GLÚ 2013 SK eng A - Abstract
Chadima, Martin
Recent advances in anisotropy of magnetic remanence: New software and practical examples.
Contributions to Geophysics & Geodesy. -, special issue (2012), s. 59-60. ISSN 1335-2806.
[Castle meeting New Trends in Geomagnetism : Paleo, rock and environmental magnetism/13./. 17.06.2012-23.06.2012, Zvolen]
Institutional support: RVO:67985831
Keywords : magnetic susceptibility * anisotropy * anisotropy of magnetic susceptibility
Subject RIV: DE - Earth Magnetism, Geodesy, Geography
http://gauss.savba.sk/GPIweb/conferences/Castle2012/abstrCastle.pdf

A very effective means of rock fabric analysis is based on the anisotropic magnetic properties, most commonly magnetic susceptibility. While anisotropy of magnetic susceptibility (AMS) is very fast and precise, it may, in certain cases, face some limitations because it reflects the sum of preferred orientation of all rock-constituent minerals. This limitation can be overcome using methods based on the magnetic remanence (Jackson 1991, Hirt 2007). The main applications of anisotropy of magnetic remanence (AMR) are i) distinguishing between the whole-rock magnetic fabric and magnetic fabric carried solely by ferromagnetic (s.l.) minerals (e.g. Hrouda 2002), ii) identifying inverse AMS fabric carried by single-domain magnetite grains (e.g. Chadima 2008); iii) assessment how the preferred orientation of ferromagnetic minerals affects the characteristic remanent magnetization of a rock (e.g. Bilardello 2009). All AMR techniques require an artificial magnetization – the most common being anhysteretic and isothermal remanent magnetizations – to be imparted along a set of independent directions. Various magnetization schemes have been proposed. We present a new hardware/software (ARem2W program) solution which includes 3-, 6-, 12-, and 15-direction designs. The user is guided through the measurement design and as soon as all necessary directions are measured, AMR tensor is calculated and expressed as the principal AMR directions (with respective confidence ellipses) together with various quantitative AMR parameters. The AMR data can be treated the same way as the AMS data and processed using, e.g., Anisoft software by Agico. The real examples demonstrating how the AMR can be used in solving various problems in magnetic fabric interpretation are discussed.
Permanent Link: http://hdl.handle.net/11104/0210593