Laguna del Maule volcanic field: Eruptive history of a Quaternary basalt-to-rhyolite distributed volcanic field on the Andean rangecrest in central Chile

The Laguna del Maule (LdM) volcanic field, which surrounds the 54-km² lake of that name, covers ~500 km² of rugged glaciated terrain with Quaternary lavas and tuffs that extend for 40 km westward from the Argentine frontier and 30 km north-south from the Rio Campanario to Laguna Fea. The distributed rear-arc volcanic field is contiguous with the Tatara-San Pedro stratovolcano complex on the volcanic front of the Quaternary Andean arc. The LdM field has had few large edifices but at least 130 separate vents have been identified, from which >350 km³ of products have erupted since 1.5 Ma. Products of 14 ice-ravaged (early and middle Pleistocene) stratocones and shields, and of ~115 monogenetic cones, domes, and lava flows, were mapped on foot, studied petrographically, and chemically analyzed. More than 70 radiometric ages were determined to calibrate the eruptive sequence. A large welded ignimbrite erupted at 1.5 Ma and was followed by another at ~950 ka, producing a 12 x 8 km-wide caldera that underlies the north half or the lake basin and rugged highlands north of it; outside the caldera, the south half of the basin is an erosional feature cut on Tertiary andesites and dacites.