The Tutupaca volcanic complex (Southern Peru): Eruptive chronology and successive destabilization of a dacitic dome complex

Several processes have been proposed as triggering mechanisms for the large sector collapses that affect most volcanoes, and which may occur several times in volcano's lifetime. Here we present discuss case of Tutupaca volcano, located southern Peru part Central Volcanic Zone Andes. is composed an old, hydrothermally altered highly eroded Basal edifice, well younger twin peaks northern complex (the Western Eastern Tutupaca). The youngest edifice at least seven coalescing lava domes associated deposits, including block-and-ash flow debris avalanche deposits. We identified two An older unit (Azufre deposit) was channeled valleys to E SE basal reaching up 3.5 km from its source region. Four cosmogenic nuclide exposure dates (10Be/feldspar) were obtained boulders this deposit ranged between 6.0 ± 0.7 7.8 1.5 ka. (Paipatja with collapse reconstructed just after first (domes IV VIII). produced a outcrops immediately NE amphitheater pyroclastic density current previously dated by radiocarbon 218 14 BP (Samaniego et al., 2015). Both deposits contrasting sub-units: (1) main subunit, hereafter called hydrothermal-altered deposit, whitish-yellow volcanic breccia heterolithic heterometric blocks, originated (2) dome-rich non-altered dome blocks Tutupaca. In proximal areas, overlaps hydrothermally-altered while distal these units are mixed forming hummocky and/or ridged topography. addition similarity both avalanches, propose mechanism avalanches similar. dacitic growth, coupled substrate older, rock, induced destabilization producing related currents.