These were specific areas set aside for Native American use. Often resulted in forced migration of the tribes onto these spaces by the army.
Homesteads
Allotments
Reservations
Casinos

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.