Global Volcanism Program | Image GVP-10484
One of the most prominent topographic features of SE Guatemala is the figure-8-shaped double caldera of Ayarza volcano. Both calderas were formed within several thousand years of each other during major rhyolitic explosive eruptions in the late Pleistocene, about 27,000 years ago (eastern caldera) and 23,000 years ago (the larger western caldera). Formation of the older caldera was accompanied by the eruption of the chemically mixed pumices of the "Mixta" unit. The city of San Rafael las Flores, 6 km to the NE, is at the upper left.
NASA Landsat image, 2000 (courtesy of Loren Siebert, University of Akron).