Refolded fold

3D Model

This beautiful hand specimen of a refolded quartz layer in a micashist invites us to think about the relative orientation of the two generations of fold axes and fold axial planes. Start with the latest (second) axial plane, can you identify it? What about the second fold axis (hinge line)? Now try to find the first hinge line - you will find that it has been bent (folded). If you identify the first fold axial plane, you will see that it has bent along with the hinge line. This does not happen in all refold geomerties, we call this a type 2 refold. How would you have to slice through the dataset to see a “mushroom”-type interference pattern typical for type 2 refolds?