A Quick Perspective:
Time, Rock and
The Lake Powell
By Gary Ladd
The Grand Canyon and Glen Canyon landscapes look ancient and one might be tempted to
believe they are truly primeval. They are, indeed, very old. But so vast an amount of time has elapsed since EarthÝs creation that these canyons might be considered upstarts.
Take a moment to examine a list of events that lend a sense of perspective.
- About 15 billion years ago.
- Oxygen begins to accumulate in EarthÝs air:
- Age of the oldest Grand Canyon rock:
- Plants begin to colonize dry land:
- About 450 million years ago.
- Animals first venture onto dry land:
- About 425 million years ago.
- Age of the youngest Grand Canyon rocks:
- Occurrence of "The Great Dying" when most of EarthÝs plants and animals perished. (The cause is
- Age of Glen Canyon area rock layers:
- Around 190 million years.
- North America begins to uncouple and drift westward and away from Europe:
- About 150 million years ago.
- Age of the Rocky Mountains:
- A giant meteor crashes into Earth near the Yucatan Peninsula, apparently causing the extinction of many plant
and animal species including the dinosaurs:
- AGE OF GLEN AND GRAND CANYONS:
- The first true humans appear in Africa:
- About 3 million years ago.
- Creation of Meteor Crater:
- America via the Bering Land Bridge:
- Creation of Crater Lake, Oregon:
- Colonization of Hawaii by Humans:
Today's scenery is newfangled. Its rocks may date to hundreds of millions of years in age but the topography
is young. The mesas and buttes that have been cleaved from the rock layers are works-in-progress. Individually they began to take shape hundreds of thousands of years ago.
Their familiar outlines began to emerge, perhaps, tens of thousands of years ago. And in most cases their details have been shaped in only the most recent hundreds to
thousands of years.
Enjoy Lake Powell. But remember to be gentle with the landscape that surrounds its
waters. The slickrock terraces, cliffs and slot canyons are newborn, unique and fragile.