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Full-Text Articles in Social and Behavioral Sciences
Astronomically Calibrated 40ar/39ar Age For The Toba Supereruption And Global Synchronization Of Late Quaternary Records, Michael Storey, Richard Roberts, Mokhtar Saidin
Astronomically Calibrated 40ar/39ar Age For The Toba Supereruption And Global Synchronization Of Late Quaternary Records, Michael Storey, Richard Roberts, Mokhtar Saidin
Richard G Roberts
The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated (40)Ar/(39)Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and …
Extensional And Colisional Magmatic Records In The Apiai Terrane, South-Southeastern Brazil: Integration Of Geochronological U-Pb Zircon Ages, Oswaldo Siga Junior, Miguel Angelo Stipp Basei, Allen P. Nutman, Kei Sato, Ian Mcreath, Claudia Regina Passarelli, Dunyi Liu
Extensional And Colisional Magmatic Records In The Apiai Terrane, South-Southeastern Brazil: Integration Of Geochronological U-Pb Zircon Ages, Oswaldo Siga Junior, Miguel Angelo Stipp Basei, Allen P. Nutman, Kei Sato, Ian Mcreath, Claudia Regina Passarelli, Dunyi Liu
Faculty of Science - Papers (Archive)
The aim of this work is the presentation of a synthesis of available geochronological data for the basement inliers and metavolcano-sedimentary sequences which occur in the southern part of the Apiai Terrane, south-southeastern Brazil. These data, especially those obtained during the last decade, have made substantial modifi cations to the tectonic scenario of south-southeastern Brazil with the recognition of the presence of extensional basins (continental rifts) with magmatism and sedimentation at the late Paleoproterozoic (1790 - 1750 Ma) and of the Mesoproterozoic (1600 - 1450 Ma). These processes started at the late Paleoproterozoic in the Betara, Perau and Apiai Mirim …
Western Pacific Coral Delta18o Records Of Anomalous Holocene Variability In El Nino-Southern Oscillation, Helen V. Mcgregor, M Gagan
Western Pacific Coral Delta18o Records Of Anomalous Holocene Variability In El Nino-Southern Oscillation, Helen V. Mcgregor, M Gagan
Faculty of Science - Papers (Archive)
No abstract provided.