Water Trickles, The Earth Heaves

Vivid geology of Sedona bears witness to the death of stars, the drift of continents, the power of water and the thoughts of rocks

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Pete Aleshire/Roundup

Darkness Falls: The placid waters of Oak Creek at dusk with the moon rising give little hint at the power and violence of a stream that has sculpted one of the most famous and dramatic landscapes on the planet.

photo

Tom Brossart/Roundup

Steep Garden: This view of a fine-grained tree on the Little Horse Trail demonstrates the topography of most of the major Sedona Rock formations, where sheer cliffs of sandstone and limestone sit on top of the crumbly, soft Hermit Formation, which forms an base on which plants

photo

Tom Brossart/Roundup

Protected formation: Cathedral Rock constitutes one of Sedona’s most visible landmarks and purportedly the site of a geomagnetic vortex. Like most of the isolated buttes that define the valley, the formation was cut by the action of Oak Creek after which the hard cap of limestone protected the soft, underlying sandstones from erosion.

Oak Creek swishes and sighs at my feet as the day dies, the rising moon reflected in its pensive waters. Lifting my eyes to the darkening form of Cathedral Rock, I try to imagine upheaval, catastrophe, flood and violence.

Nothing.

How do you think like a rock? Might as well ask an aphid to imagine building a spaceship and visiting the moon.

Darn. This is hard.

I sit on the water-smoothed sandstone, focusing for a moment on the potholes eroded into the stone — really the fossilized remnants of sand dunes that wandered across a Sahara-sized desert back before the dinosaurs started their long, doomed run.

Taking a deep breath of imagination, I look up again at Cathedral Rock and try to picture how the placid creek at my feet could have moved a mile-deep layering of rock — eating back into the uplifted edge of the Colorado Plateau and leaving these remarkable buttes standing like castles in its path.

I focus in the dimming light on the layers of white in the massive face of Cathedral Rock as well as the white cap of lighter rock.

Ah. Got it. Just a click of understanding, the faintest appreciation of time and the season’s of the earth, where a million years are but a moment — the human equivalent of lunch at Burger King.

The light layers are composed of limestone, sedimentary rock made of the calcium carbonate skeletons of near-microscopic sea creatures.

For just a moment, I could sense in those ghostly layers of white the restless shift of continents, the rise and fall of oceans, the pulse of the Earth. No wonder people claim they can feel the swirl of a mystical geo-magnetic vortex in this spot.

My triumph of imagination lasts only a moment, a flush of insight and awe. Then my pathetic human time scale reasserts itself and I’m left with only the awe.

But I have tromped all over the remarkable geological revelation of Sedona, a junkie for that moment of insight. The fabled rusted-red sandstone and limestone buttes of Sedona are intimately connected to Rim Country, since they lie along the same uplifted Mogollon Rim that defines the Payson area as well. In fact, another Sedona lies hidden beneath our feet — the buried layers of ancient sand dunes, hardened limestone and volcanic outpourings. In the fullness of time, Tonto Creek, Fossil Creek and the East Verde will reveal that buried landscape — as Oak Creek has done in Sedona.

The rich, recent history of the earth is vividly chronicled in Sedona, a 300-million-year-old touchstone for the breakup of a supercontinent, the scattering of its fragments, the construction of North America and finally the uplift of the Colorado Plateau. The unimaginable uplift has shaped the landscape of the modern West — from the glacial tips of the Rocky Mountains to the sweltering depths of the Grand Canyon.

And if that’s not enough, the very color of the rocks connects to the deaths of stars. Sedona’s buttes gain their distinctive red coloring because of the dissolved iron seeping into the pores of the rock — then rusting in its reaction with oxygen, binding together the sand grains in the process. Turns out, the only way to make iron is in the intense heat and pressure at the core of a star. The only way to distribute that iron is for the star to explode in a supernova. So the red of those buttes bears mute witness to the complete life cycle of a massive star.

The complicated sequence of mountain building, erosion, subsidence and renewed uplift all lie revealed in the naked rocks of Sedona.

Geologically speaking, Sedona remains a brash child, with its careless spires, bright colors and rapid erosion — with most of the visible rocks less than 320 million years old.

Just across the way, on the opposite side of the Verde Valley beneath Jerome, lie much older rocks — 1.8-billion-year-old schists. At one point, those rocks were buried by the collision of continents, then fractured and remelted by the resulting volcanism. The superheated water moving through undersea volcanic vents likely produced the deposits of gold, silver and copper that sustained the mines of Jerome.

But the more sedate and recent landscape of Sedona reveals more about the layering of time and the enormous power of erosion.

Most of the Sedona rocks were laid down as either sand dunes or sea bottom limestones, the white, flat bands. Throughout Sedona, the buttes generally show a broad base made of soft Hermit Formation laid down by the floodplain of a great river 270 million years ago. Above that generally rises a sheer, red sandstone cliff, made from harder, rusted sandstones. Near the top of most of those buttes lie the sea bottom limestone layers, whose resistance to erosion account for the existence of the big central formations like Cathedral Rock, Bell Rock and Courthouse Rock, since the limestone layer protects the softer sandstone beneath from erosion.

Most of those rock layers were formed just before the first dinosaurs arrived on the scene, when all the major continents were gathered into a single, supercontinent called Pangea. As the continents broke apart due to still only dimly understood currents in the Earth’s molten mantle and core, millions of years of erosion buried, compressed and hardened those layers.

As the continents shifted to their current positions, a still poorly understood period of uplift started. Between 80 and 40 million years ago, the central mass of North America heaved itself up by a mile or two — uplifting the Rocky Mountains to their current height.

That long, slow-motion upheaval created the distinctive landscape of Sedona — and all the rest of Rim Country.

The 2,000-foot cliffs of the Mogollon Rim mark the southern edge of that upheaval, a line of cliffs across the middle of Arizona, broken only by the major drainages — like Oak Creek.

A series of volcanic eruptions some 15 million years ago added the final element to the landscape, surfacing much of the top of the Rim with a hard, erosion-resistant layer of volcanic rock.

Time and erosion provided the final artistic touches. Stream drainages cut through the lava cap along the Rim and chewed into the softer sedimentary rocks beneath, creating the steep, dramatic canyons of Oak Creek, Fossil Creek, Tonto Creek and the East Verde, each of which descend in a short distance through more than 3,000 vertical feet.

Farther north, the same process created the Grand Canyon, magnified because the Colorado River drains perhaps a huge swath of the continent.

Eventually, Oak Creek and the other major streams cutting into the Mogollon Rim will work their way backward to connect to the Grand Canyon as gravity and erosion team up in their relentless obsession with wearing every mountain down to beach sand.

I run through all those thoughts, my mantra of imagination, as the darkness gathers — until even the ghost cap of Cathedral Rock disappears into the darkness caused by yet another spin of the planet. The haunted moon hangs in the sky, dead and white — pockmarked with 4-billion-year-old craters. The poor moon had not enough mass to hold onto its internal heat, so it had no molten core, no crustal plates, no volcanoes, no oceans, no erosion — a dead, blasted hunk of rock.

So I sit in the dark and listen to the sound of the water, that trickle of change that can carry even the greatest of mountains finally to the sea. And in the seams of that sound, I try again to hear the breath of the earth, measured in millions of years — even here in the vortex.

There — just for an instant. Did you hear it?

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