With over 50 million modern human lifetimes elapsed since the planet formed around 4.5 Ga, geologic or deep time is, to say the least, difficult to grasp.
But the effort pays, for with a feel for deep time comes a sense of its great power: Given enough time, almost anything energetically possible can happeneven at very large scales.
If you need more help with geologic time or terminology, check out these resources.
Colorado's geologic history is as complex as it is fascinating.
With the formation of the earth pegged at h (midnight), our work day finishes at h, just as we pull up to the present. Each hour corresponds to 0.875 billion years (Ga), each minute to 3.125 million years (Ma) and each second to 52.1 thousand years (Ka).
Conversely, 1 Ga takes 4 hours, 20 minutes out of the day; 1 Ma, 19.2 seconds; and 1 Ka, 19.2 millisecondsliterally the blink of an eye.
This geologic overview focuses primarily on the Colorado Rockies and the Colorado Plateau, but adjoining portions of Wyoming, Utah and the High Plains as far east as the Black Hills of South Dakota also have important and related stories to tell.
Throughout this article, I'll refer to Colorado and these adjoining areas as our region of interest, which closely coincides both with the area shown in the NASA photo at Bearings just below and also with the area affected by Laramide uplift.
And so it goes with the bending of seemingly rigid rocks, the cutting of majestic canyons, the raising and erasing of entire mountain ranges, the opening and closing of globe-girdling oceans, and the incessant splitting and regrouping of the dancing continents.
Our usually reliable day-to-day sensibilities tell us that such things can't happen, but they can and do happen because solid rock reveals its malleability only over time scales very long compared to human eventstypically in spans of tens of thousands if not millions of years.
Colorado's generous endowments of accessible mineral wealth and fertile farmland were not inevitable birthrights. This overview ventures a "to the best of our knowledge" summary of Colorado geologic evolution current as of late 2004.