The answer to your question is perceptual
Answer:
Rivers transport particles, from fine ones such as silt in turbid water to coarser ones such as sand, gravel, and boulders associated with bed-load transport. The speed and turbulence of currents enable transportation of these materials. When riverbed gradient or the river flow diminishes, particles tend to drop out.
Explanation:
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This is called the Rule of Superposition. ... With absolute age dating, you get a real age in actual years
