@article {2712, title = {In situ cosmogenic 3He and 36Cl and radiocarbon dating of volcanic deposits refine the Pleistocene and Holocene eruption chronology of SW Peru}, journal = {Bulletin of Volcanology}, volume = {81}, year = {2019}, month = {Jan-11-2019}, abstract = {Constraining the age of young lavas, which generally fall outside the effective range of traditional geochronology methods, remains a key challenge in volcanology, limiting the development of high-resolution eruption chronologies. We present an in situ cosmogenic 3He and 36Cl surface-exposure chronology, alongside new minimum-limiting 14C ages, documenting young eruptions at five sites in the Western Cordillera, southern Peru. Four 3He-dated lavas on the Nevado Coropuna volcanic complex (hitherto thought to be dormant) indicate that the central dome cluster is young and potentially active; two Holocene lavas on the easternmost dome are the youngest directly dated lavas in Peru to date. East of Coropuna, lava domes and block-lava flows represent the most extensive output to date of Nevado Sabancaya, one of Peru{\textquoteright}s most active volcanoes. Two 3He measurements confirm the Holocene age of these deposits and expand the chronology for one of the youngest major lava fields in Peru. 36Cl surface-exposure ages from the Purupurini dome cluster and Nevado Casiri document middle-late-Holocene episodes of effusive activity, while basal 14C ages from a lava-dammed wetland constrain an effusive eruption at Mina Arcata, north of Coropuna, to the late-glacial period. These new data advance the recent Western Cordillera volcanic record whilst demonstrating both the considerable potential and fundamental limitations of cosmogenic surface-exposure methods for such applications.}, issn = {0258-8900}, doi = {10.1007/s00445-019-1325-6}, url = {http://link.springer.com/10.1007/s00445-019-1325-6}, author = {Bromley, Gordon R. M. and Thouret, Jean-Claude and Schimmelpfennig, Irene and Mari{\~n}o, Jersy and Valdivia, David and Rademaker, Kurt and del Pilar Vivanco Lopez, Socorro and Team, ASTER and Auma{\^\i}tre, Georges and Bourl{\`e}s, Didier and Keddadouche, Karim} }