Folds - Alaska

These are very small folds in silici-clastic meta-sediments from an outcrop on the road into Valdez Alaska, with the entire horizontal field of view only 8 cms or so. A closer look will bring to light that there is a lot more going on here structurally that might be initially apparent. Find and trace the following: 1) folds, 2) parallel spaced veins and other surfaces aligned with fold hinge (where layer bends most sharply) zones, and 3) isoclinal fold hinges where the layer wraps around so completely that one limb is parallel to the other (you will need to look carefully to find these).

Question that may be raised include the following. Why is the layering being folded so discontinuous and irregular? What is the significance of the isoclinal fold hinges? What type of setting would produce this geometry?

Link to interpreted image.

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