Fractography: fracture topography as a tool in fracture mechanics and stress analysis. An introduction

The term fractography was first used by the metallurgist Carl A. Zapffe (Zapffe & Clogg 1944), and was introduced to geology by Byron Kulander in the 1970s (Kulander et al. 1979). The discipline of fractography (as a science) in geology is therefore new, even though nearly a century ago Woodworth (1896) was the first to describe joint surface morphology from field observations. Fractography is hardly mentioned in text books on structural geology, consequently many geologists are unfamiliar with this term and its implications and may confuse the term with fractals. The subject is largely neglected by those who deal with fracture characterization of rocks (e.g. core laboratories) in spite of its obvious potential. In addition, the interpretation of fracture surface features in rocks has been almost exclusively qualitative, and frequently controversial. The state of infancy and neglect of fractography in geology is further reflected by the fact that in this field there has been no clear definition of fractography. In addition there is no universally accepted, unified nomenclature for fractographic features. All these factors prompted this special publication, the first thematic volume on fractography in geology.