https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3322 5 m thick flowstones whose top-beds have an age exceeding the limits of U/Th alpha spectrometric dating (>350 ka). Cave morphology and chronological constraints obtained from speleothems suggest that an important uplift event occurred during the Middle Pleistocene following a period of tectonic standstill of probable latest Early Pleistocene age. Active spring caves close to present-day valley floors contain speleothems whose ages exceed 100 ka, implying that no significant downcutting of the seaward valleys, and consequently no tectonic uplift, has occurred during Late Pleistocene.]]> Sat 24 Mar 2018 07:23:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45464 26Al and ¹⁰Be) in quartz grains allowed to estimate a minimum burial age of 5.25 Ma based on the mean sediment transport time at the surface and infer original altitude of the catchment area. Detrital apatite fission-track (AFT) and U-Pb dating on zircons provide information on the source, both from a regional and altitude (exhumation) perspective. Two populations of detrital AFT ages center at 17 (−2.3 + 2.6) Ma and 23 (−3.3 + 3.9) Ma, whereas the main detrital zircon U-Pb age populations are younger than 40 Ma. These correspond to intrusive and metamorphic sources nowadays outcropping exclusively above 2,200–2,300 m a.s.l. in Northern Adamello and Tonale. The results point to a late Miocene erosion and infilling of the cave by allochtonous sediments, with important implications on the timing of cave speleogenesis, as well as the paleogeographical connection, tectonic evolution and uplift of different structural units of the Alps. The roundness and the well sorted size of the quartz grains suggest a fluvial or aeolian origin, possibly recycled by glacial activity related to cold events reported in high latitude areas of the world at 5.75 and 5.51 Ma. These glacial phases have never been documented before in the Alps. This information confirms that the valleys dividing these geological units were not yet deeply entrenched during the onset of the Messinian Salinity Crisis (5.6–5.5 Ma), allowing an efficient transport of sediments across major tectonic lineaments of the Alps. This study shows the potential of cave sediments to provide information not only on the age of speleogenesis but also on the paleogeography of a wide area of the Alps during the late Miocene.]]> Fri 28 Oct 2022 14:30:18 AEDT ]]>