Stress and Strain:
Squashing Rocks in the Muav Gorge

   Chuck Barnes of NAU Geology suggested that a geologist should seek out a beautiful field area first, and ask questions later. I took him at his word; while stumbling through a master’s at Stanford, I chose the Grand Canyon for a thesis area.

   Perhaps you’ve noticed the folds and faults in the Muav at river level near Kanab Creek. The folds come in a number of different flavors: wavy thin-bedded limestones that hang above the river around Last Chance; or stubby little “kink bands”, where an eight- or ten-foot segment of bedding is suddenly tipped twenty or thirty degrees steeper than the surrounding rock. Consider the limestone immediately upstream of Olo; a thrust fault blasts out of that wall with all the impatience of a locomotive leaving its tracks. In some places, the deformation is more subtle: walk down a side canyon like Matkatamiba, and you will see beds bend

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