Global Volcanism Program | Image GVP-06223
The low hill covered by fields (left-center) is Pico do Gaspar lava dome, which lies east of Lagoa das Furnas. Plinian eruptions about 1100 years ago including local pyroclastic flows accompanied formation of two nested pumice rings. An arcuate line of trees about halfway between the lake and the summit of the lava dome marks the rim of the northern pumice ring. The eruption concluded with emplacement of the Pico do Gaspar trachytic lava dome.
Photo by Rick Wunderman, 1997 (Smithsonian Institution).