Part D: Is the conceptual model developed in Part 1 consistent with your data? There is a big jump in the "order of magnitude: 20 to 385 to 2945 between 20 m/Ma plateau downward erosion 385 m/Ma river incision 2945 m/Ma canyon widening Data gathered from this location in the Grand Canyon not disprove the conceptual model. The rate of plateau lowering is much lower than the other two (incision, widening) processes. The rate of widening is much more the rate of river incision. This is consistent with the model in the previous lab, where the existence of the Grand Canyon requires that plateau erosion be slow. Also, a wider canyon than a deeper canyon means that the rate of widening is faster th