@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} } @article {2685, title = {Holocene history of the Greenland Ice-Sheet margin in Northern Nunatarssuaq, Northwest Greenland}, journal = {arktos}, volume = {4}, year = {2018}, month = {Jan-12-2018}, abstract = {Records of past Greenland Ice-Sheet (GrIS) extents are important for understanding the response of the ice sheet to climate conditions, providing a longer term perspective on present ice-margin fluctuations, and evaluating ice-sheet models. We present a record of Holocene GrIS extents in Nunatarssuaq, Northwest Greenland, based on geomorphic mapping combined with 10Be surface exposure dating of rock surfaces and 14C dating of subfossil plants. 10Be ages of boulders and bedrock exposed during deglaciation from the Last Glacial Maximum range from ~ 81 to 15 ka. The apparently old ages of some samples and scatter in the dataset indicate the presence of 10Be inherited from prior periods of exposure and suggest that overriding ice was minimally erosive. Subfossil plants exposed on a debris band in the GrIS margin date to ~ 4.7 cal ka BP and register a time when the Northwest GrIS was smaller than at present. Geomorphic evidence, including a drift sheet, grounding-line moraines, and higher levels of Nords{\o}, document an advance of the Nuna and Tunge Rampen (GrIS outlet glaciers). 14C ages of in situ subfossil plants and 10Be ages of boulders bracket this advance to ~ 3.2{\textendash}2.1 ka, a period of regional cooling. Unweathered, lichen-free drift occurs < 50 m beyond the present GrIS margin in most locations. 10Be ages of this drift are 2.2{\textendash}0.5 ka and likely contain inherited nuclides. 14C ages of in situ subfossil plants atop this drift are between cal AD ~ 1640 and 2001, suggesting recent ice-margin fluctuations.}, issn = {2364-9453}, doi = {10.1007/s41063-018-0044-0}, url = {http://link.springer.com/10.1007/s41063-018-0044-0http://link.springer.com/content/pdf/10.1007/s41063-018-0044-0.pdfhttp://link.springer.com/article/10.1007/s41063-018-0044-0/fulltext.htmlhttp://link.springer.com/content/pdf/10.1007/s41063-018-0044-0.pdf}, author = {Farnsworth, Lauren B. and Kelly, Meredith A. and Bromley, Gordon R. M. and Axford, Yarrow and Osterberg, Erich C. and Howley, Jennifer A. and Jackson, Margaret S. and Zimmerman, Susan R.} } @article {104, title = {Extensive recession of Cordillera Darwin glaciers in southernmost South America during Heinrich Stadial 1}, journal = {Quaternary Science Reviews}, volume = {62}, year = {2013}, note = {id: 2331}, pages = {49-55}, abstract = {The geographic expression and phasing of events during the last termination are important for isolating mechanisms that caused Earth to emerge from the last ice age. Heinrich Stadial 1 (HS1; 14,600{\textendash}18,000 yr BP) is a key because of the central role that its far-field effects had on the last termination in the Southern Hemisphere. Here, we present new data from Cordillera Darwin that show rapid glacier recession in southern South America during HS1. This retreat was coeval with ice recession elsewhere in South America and New Zealand, with increased upwelling in the Southern Ocean, with warming of SSTs offshore of Chile, and with a rise in atmospheric CO2. Together, these data indicate a coherent and rapid response to the effects of HS1 in the middle and high latitudes of the Southern Hemisphere.}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2012.11.026}, url = {http://www.sciencedirect.com/science/article/pii/S0277379112005057}, author = {Hall, Brenda L. and Porter, Charles T. and Denton, George H. and Lowell, Thomas V. and Bromley, Gordon R. M.} }