Fission-track dating of the punta de vacas glaciation in the Rı́o Mendoza valley, Argentina.

摘要: Abstract Fission-track dating of three tephra samples related to mappable drifts and non-glacial sediments, including alluvium, in the Rio Mendoza valley, Argentina, places limiting ages on oldest two glacial events. A tephra-layer interstratified with fan alluvium that surrounds cuts outermost Uspallata moraine has an age 170,000±50,000 yr, implying drift predates marine oxygen isotope stage (OIS) 6. dated at 134,000±32,000 yr, was deposited alluvial underlies Punta de Vacas drift, which is inferred equate Isotope Stage The outwash, likely correlates Colorado overlies another unit dates 260,000±150,000 yr. Although error limits preclude definitive correlations, all units may have been during interval prior maximum advance glaciation OIS 6 or maybe 7 interglacial period.