By modern scientific calculations, the earth is many millions of years old.
The Absolute Geologic Time Scale has been developed by using a process called “Isotopic Dating”, in which the decay rates of certain radioactive materials are established and measured, then used as “clocks” to calculate the ages of various rocks.
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But as new techniques are developed to tease ever more information from the canyon's rocks, the age of the canyon becomes more of a puzzle. Geologists know that the canyon and the river had to have formed within the last 80 million years because this is when the sea was last present here.
Traditionally, the age of the canyon is ascribed at 6 million years but this date refers specifically to when the modern Colorado River came into existence. When the landscape was uplifted from this seabed, an initial river system developed and drained to the northeast, exactly opposite to the flow direction of the Colorado River today.
The Grand Canyon is one of the most recognizable landforms on planet Earth and the most often asked question about it is, "When did it form? Geologists still debate many of the details about the origin and age of the canyon but recent geologic research has shed new light on the topic.
Using new, sophisticated laboratory techniques geologists are able to tease ever more information from the canyon's seemingly stubborn rocks.