Global Volcanism Program | Image GVP-08220
The El Valle de Antón SW caldera rim reaches 300 m above the caldera floor. The caldera formed during major explosive eruptions about 1.1-1.3 million years ago. A former caldera lake contributed to phreatomagmatic and phreatic eruptions that continued into the late Pleistocene. More than 90 m of lake sediments were deposited on the caldera floor prior to draining of the lake.
Photo by Lee Siebert, 1998 (Smithsonian Institution).