Superior, Arizona, just a couple of miles east of the BTA, sits at the base of a geological formation known locally as Apache Leap. The cliffs of the Leap are composed of a dark volcanic tuff squeezed from the earth’s bowels around 25 million years ago. In the hills beneath the cliffs, one sees layered bands of gray sedimentary rock – once a seabed but now faulted limestone – having originated during the Carboniferous Period. In this limestone, one finds the remnants of organisms that populated the ancient seas – mostly brachiopods, bivalves, and crinoids.
My partner Lori and I hiked up to study a few of those limestone outcroppings. We found a slab about 30’ long and 8’ high, composed mostly of a dense conglomeration of fossilized shells. We walked along that wall, brushing our hands thoughtfully across a solidified expanse of time. [Read more…]