Chachimbiro

The Chachimbiro volcanic complex lies about 25 km NW of the city of Ibarra. Late Pleistocene collapse of the andesitic Huanguillaro stratovolcano produced a 6.8 km3 debris-avalanche deposit and a 4-km-wide avalanche caldera open to the east that has largely been filled by lava domes, including the rhyodacitic Hugá dome. The avalanche deposit is overlain by three large ignimbrites and pyroclastic-flow deposits related to dome growth. The late Pleistocene-to-Holocene, NNE-trending, dacitic Chachimbiro-Pucará line of lava domes includes the Pitzantzi dome, which erupted about 5,700 years ago, producing an ash deposit that extends to the NW. Hot springs and thermal areas are present in the complex.