The River Valley Civilizations government and organization were needed for:

Early river civilizations were all hydraulic empires that maintained power and control through exclusive control over access to water. This system of government arose through the need for flood control and irrigation, which requires central coordination and a specialized bureaucracy.

peace keepers

idealism to be spread

riches kept

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.