Some islands have older islands at one end of the chain and younger islands at the other end. Example is the Hawaiian Islands.
Explanation:
Volcanic mountains or islands are formed when the tectonic plates in the earth’s crust converges. The string of Hawaiian volcanic islands were formed as a result of the movement of the Pacific plate over a fixed hotspot, where the magma rises upward and erupts on the seafloor. The northwestern islands are older than the islands to the southeast side of the Hawaiian islands.
The age of a volcanic rock is calculated by measuring the amount of argon and the amount of radioactive potassium present in the rock. These measurements are the supporting evidence which showed that the southeastern end of the chain is younger than the northwestern part of the chain. The volcanic islands gradually subside and erode as they age, so the older islands have much lower elevations than the newer islands. This is another evidence which supports the conclusion.
