 Ages of particular blue-ice areas have been inferred from the ages of the meteorites there discovered, although redistribution of meteorites between various areas through ice flow can cause this procedure to yield erroneous age estimates.The oldest blue-ice areas may be up to 2.5 million years old and the ice in them can be quite old as well, with ages of several hundred thousand years estimated on the basis of ice flow dynamics and radiometric dating and the development of a horizontal stratigraphy.This occurs because ice blocked by obstacles stagnates and moves at a rate commensurate with the ablation rate.