Abstract:

Petrofabric analysis is one of the important work in structural geology, and plays a critical role for our understanding of many geological processes. Petrofabric subject traces its origin to the early twentieth century, and do much to the earth science with the great developments of theories and techniques ever since. Professor Chi Jishang was one of the most important founders of petrofabric subject in China, and did invaluable contributions to its developments. In the last 10 years, the electron backscatter diffraction (EBSD) technique has developed into a powerful tool for the study of petrofabrics in the scanning electron microscope (SEM). The quantitative crystallographic orientation data from EBSD have a wide variety of potential applications in geology, including phase identification, studying deformation mechanisms, crystallographic preferred orientation analysis, constraining dislocation slip systems, studying metamorphic processes and more. This paper briefly describes some of the physical fundamentals and the practical setup of the technique and its application scope in geology. The advantages and disadvantages of EBSD as compared to some traditional methods such as universal stage, Xray diffraction, neutron diffraction and transmission electron microscope (TEM) are also discussed. Finally, we presented here an application example of the petrofabric study of garnet and omphacite in the DabieSulu ultrahigh pressure eclogite.

Key words: petrofabric, EBSD, CPO, eclogite, garnet, omphacite