A recent news article reported that more than three million tourists will have visited the Grand Canyon during the summer of 2000 (Blaksee, 2000), that they would stand in awe at the top of the rim, turn to a guide and ask, "How'd that happen?" During a Grand Canyon-Colorado Plateau Geology Symposium attended by 70 geologists, Dr. Richard Young mused, "The public always wants to know how the Grand Canyon was formed and they don't realize we don't know either The debate will go on for many years" (Anonymous, 2000; p. geology3).
Geologists do agree on the canyon's age - six million years - and that it offers a wealth of information. Aside from its breathtaking beauty and awe, one of the factors holding allure for geological study is that information is so readily accessible (Anonymous, 2000; p. geology). The cuts made either by the Colorado River or some other ancestral river that flowed in the other direction leaves layer upon layer exposed for the study. Geologists take advantage of the opportunity, and continue to debate the canyon's origins.
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The Known Facts.
One author is eloquent in explaining the Grand Canyon's geological appeal:.
The Grand Canyon's greatest significance lies in the geologic record that is so beautifully preserved and exposed in its walls. What is unique about the canyon's geology is the great variety of rocks present, the clarity with which they're exposed, and the complex geologic story they tell (Anonymous, 2000; p. geology).
Though the canyon itself is geologically very young, the layers of rock and sediment it has cut through are not. Therein lies the geological appeal of the canyon. Many layers of stratification are accessible for geological study in the Grand Canyon as in no other area. There are deeper canyons in the world, but none graced with such extensive geological information along its margins.
This arrangement of conditions - a geologically young canyon cut through geologically old rocks - provides a setting in which there is contained two separate geologic stories.