 Trace element patterns are distinct in the Galán ignimbrite in comparison to the Toconquis Group rocks.The formation of the Galán magma has been explained with melting of lower crustal rocks under the influence of rising basaltic magmas that supplied the heat needed for the melting processes, and which also directly contributed to magma formation through mixing events.Further metasomatism in the crust and fractional crystallization processes completed the magma genesis process.