THE ANALYSIS OF PROGRESSIVE DEFORMATION IN ROCK ANALOGS

Two-dimensional deformation experiments using analogue materials such as octachloropropane and camphor have proven to be a powerful tool in the investigation of microstructural development, since they make it possible to observe the specimen throughout its deformation history. The addition of dispersed marker particles makes it possible to trace the movement of material points during deformation. From this information the flow and deformation can be interpolated for any point within the specimen at any time. The geometry of the flow and deformation can then be visualized in the form of grids, contour-plots, strain ellipses and other methods. Despite this apparently ideal setting for studying flow and deformation, the need to use marker particles to trace material points introduces unexpected problems in the analysis. We present a computer program to analyse the movement of marker particles. Digitization of the positions of the particles is improved by the use of video input and semi-automatic digitization. The use of polynomials to describe the complete path of marker particles and least-squares best-fit solving improves the analysis of the data.