Luminescence chronology of fossiliferous fluvial sediments along the middle Atbara River, Sudan

Fluvial sediments of the middle Atbara River Valley, eastern Sudan, contain abundant vertebrate fossils and stone tools. Previous work described two sedimentary units, Butana Bridge Synthem (BBS) Khashm El Girba (KGS), with three divisions each (BBS1-3 KGS1-3, from bottom to top, respectively). 230Th/U dating on bivalve shells suggested an age ∼126 ∼92 ka for basal KGS2 KGS3, respectively, mammalian biochronology in combination magnetostratigraphy late Early early Middle Pleistocene underlying BBS. To establish a detailed chronology this fluvial sequence, we collected 17 luminescence samples both sides close Bridge. Quartz OSL was applied upper part profile (upper KGS3), but signal reached saturation within ∼10 m sequence. select suitable feldspar date older beyond limit quartz OSL, comparison post-IR IRSL at 225 290 °C, pulsed 50 °C conducted sample KGS3. The result showed that only fading corrected yielded consistent signals (both °C) overestimated significantly. We therefore selected deposits. ages indicate entire BBS - KGS sequence deposited between 224 ± 23 <17 1 ka, corresponding marine isotope stages (MIS) 7–2, significantly revising previous conclusions.