"You darkness, that I come from, I love you more than all the fires that fence in the world," wrote the poet Ranier Maria Rilke.
It was a bright day when John Perry, the Berea College forester, took me on a walk along the precipitous edge of the Cumberland Plateau in Kentucky. We stood on 350 million year-old rocks and looked out across the Blue Grass country, and tried to imagine what Daniel Boone must have felt when he stood on a similar outcrop nearby (was it this one?) and saw what must have seemed the Promised Land.
The cliffs are marine limestone, laid down at a time when this part of the country was a shallow inland sea. Here is a fossilized branching coral that Perry's assistant picked up and gifted me, a frozen moment of the past, on the eve of the great continental collision that heaved the Appalachians into the sky. As the crust ascended, a sunny coral sea teeming with life was folded into the mountains' cold, dark roots.
Millions of years of the planet's hidden history are now exposed in the limestone cliffs, layered like the pages of a book. This is the darkness that we come from. We and the corals are one.
"The past is continually erased, and the record of the most distant time survives only by a chain of minor miracles," wrote the paleontologist Richard Fortey. Like the miracle here in my hand.