The topics covered in this book encompass the principl results of field investigations, analyses of meso-scale and micro-scale textures and structures, laboratory experiments, chemical analyses, conceptual fault models, as well as the implications of fault related pseudotachylyte an its related fault rocks for our understanding of earthquakes. We hope that this book helps to bridge the gap between seismology and geology and that it encourages further studies of earthquake and seismic faulting processes.