The scenic lake-filled Cuicocha caldera is located at the southern foot of the sharp-peaked Pleistocene Cotacachi stratovolcano about 100 km N of Quito. Both Cotacachi and Cuicocha were constructed along the Otavalo-Umpalá fracture zone. Eruptive activity began about 4500 years ago and continued until about 1300 years ago. The 3-km-wide, steep-walled caldera was created during a major explosive eruption about 3100 years ago that produced nearly 5 km3 of pyroclastic-flow and fall deposits. Four intra-caldera lava domes form two steep-sided forested islands in the 148-m-deep lake. A pre-caldera lava dome is situated on the outer E side of the caldera. Pyroclastic-flow deposits cover wide areas around the low-rimmed caldera, primarily to the east. Gas emission continues from several locations in the caldera lake.
The scenic lake-filled Cuicocha caldera is located at the southern foot of the sharp-peaked Pleistocene Cotacachi stratovolcano (top center) about 100 km north of Quito. Farmer's fields encroach on the rim of the 3-km-wide caldera, which was created during a major explosive eruption about 3100 years ago. Dacitic lava domes form two forested islands in the caldera lake. Pyroclastic-flow deposits from the caldera-forming eruptions cover wide areas in now populated areas below the low-rimmed caldera.
Photo by Patricio Ramon, 2003 (Instituto Geofisca, Escuela Politecnica Nacional).
Last updated 2019-12-03 09:00:03