Book excerpt: GEOPHYSICAL APPROACHES IN GEOLOGICAL STRUCTURE ASSESSMENT This book illustrates how geophysical methods can be used in subsurface investigations and exposed outcrops. It was written to share the knowledge of geophysical approaches (2-D resistivity, seismic refraction and ground magnetic) applied in making assessments towards geological structures. Furthermore, it presents, in detail, the importance of these methods in delineating the subsurface features with the purpose of enhancing the comprehension regarding the knowledge and concepts of the geophysical methods. This book accordingly compiles several case studies to capture the readers' interests and to ease their understanding. The geophysical methods used are non-destructive, rapid, relatively economic, and can vastly improve the characterization of the subsurface features. The correlation with geological parameters is used to validate the geophysical results for improved interpretations and analyses. The authors foreseen that this book has the potential to better expand the knowledge and share the experiences with those from the same field or to someone new to it.