The foundation of structural geology lies in understanding how rocks respond to force. Fossen provides a lucid explanation of the stress tensor and the concept of strain. Where many textbooks get bogged down in the mathematics of deformation, Fossen uses graphical methods to explain how rocks stretch, shorten, and change shape. The PDF format is particularly useful here, allowing students to zoom in on the vector graphics and matrix notations for clarity.
Focus on and Structural Elements . Fossen introduces the concept of deformation , strain , and stress with unparalleled clarity. Pay special attention to Figure 2.33 (the Mohr circle diagram) – it will reappear for the rest of your career.