How Has Magma Changed Over The Years

The magma has changed a great deal over the years. One example is the silica weight percent peaked at 100,000 and 200,000 years and was the lowest in the last eruption. This indicates that Hawaii might have had more felsic lavas and more explosive eruptions 100 and 200 thousand years ago than in 1959. The weight percent of K2O and Na2O of the lava has also fluctuated throughout the years.These changes are the result of the magma changing from andesite rich lava to more basalt rich over time. The magma from 100 and 200 thousand years was very andesite rich while the magma from less than 10,000 years is almost completely basaltic lava. When the magma was andesite rich the rocks formed were trachyte and trachyandesite. When the magma increases