Exercise 13
Two quartz-feldspar veins cutting across schist foliation are displayed on the right side of the Photograph below and barren fractures occur on the left. The two quartz-feldspar veins have the same strike, roughly N70E, but they have high dips in opposite senses and crosscut each other. There are also fractures that mimic the schist foliation, even at the fold hinge. What type of fractures are the infilled ones (i.e., the veins)? What are the tectonic regime and the principal stresses orientation? Present the evidence that justifies your answers.
