I'm Cara, Associate Professor of Structural Geology at the University of Nebraska-Lincoln. In this photo, I'm standing with my hand on a slip surface in the Mosca Window of the Sangre De Cristo Mountains, CO, on the flanks of the Rio Grande Rift, teaching my students about slip lineations. You can use the "steps" in the lineations to tell which way the missing fault block moved - in this case, the missing block moved down, making this likely to be an example of bedding plane flexural slip.