Magnetic Fabric of Rocks: Theory, Applications and Practical Guidelines

This workshop will provide a very brief and concise overview of techniques for investigating rock fabric using anisotropic behavior of magnetic properties with a main focus on anisotropy of magnetic susceptibility (AMS). The workshop will be divided in two parts. First, in a form of a short lecture, the concept of magnetic fabric will be theoretically introduced and the main means of fabric visualization and quantification will be defined. This will be followed by a brief overview of applications involving multiple case examples from sedimentary, igneous, and metamorphic rocks.

In the second part of the workshop, participants will be provided with several examples of magnetic anisotropy data files and will be practically guided on how to process these data using Anisoft and accompanying software. Data processing will include data visualization in various coordinate systems, mean tensor calculation, contour plots of principal anisotropy directions, data classing according to various criteria, tensor addition and subtraction, modelling of fabric overprint, and fitting of anisotropy tensors to measured directional susceptibility or magnetic remanence data. Anisoft software is available at www.agico.com