Estratigrafía preliminar del flanco Este del volcán de Santa Ana

We present the eruption sequence for the east flank of Santa Ana volcano, which we divide into the sections above and below the Tierra Blanca Joven (TBJ) formation. The sequence below the TBJ suggests a series of mafic magmatic eruptions that began before 7,800 cal BP and continued until after 5,800 cal BP. These eruptions emplaced tephra-fall and pyroclastic-density-current deposits. The sequence above the TBJ are deposits from recent eruptions during the last 1.5 ky. Most of these eruptions were phreatomagmatic with associated pyroclastic surges. The two sequences demonstrate a shift in eruptive style possibly related to an increase in water volume in the hydrothermal system.