Question

The Colorado River has been forming the Grand Canyon in Arizona for at least 6 million years. During this time, the river has slowly caused erosion of the rock. As the rock eroded, soil eroded as well, and plant populations have had to adapt to live in increasingly rocky conditions. The river continues to deepen and erode the canyon at a rate of a few milimeters per year. What geologic principle is this an example of?
A.
geographism
B.
catastrophism
C.
gradualism
D.
uniformitarianism

Answer 1

This scenario best exemplifies **D. uniformitarianism**. The principle of uniformitarianism suggests that the processes shaping the Earth today, such as erosion and sedimentation, have been occurring in the same manner throughout geological history. The gradual erosion of the rock by the Colorado River over millions of years, leading to changes in the landscape, aligns with this principle.