Generating long chronologies for lacustrine sediments using luminescence datingA 250,000 year record from Lake Tana, Ethiopia

Authors Organisations
Type Article
Original languageEnglish
Pages (from-to)66-77
Number of pages12
JournalQuaternary Science Reviews
Volume202
Early online date17 Nov 2018
DOI
Publication statusPublished - 15 Dec 2018
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Abstract

The lakes of the eastern Africa Rift often contain great thicknesses of sediment that may provide continuous records of environmental change over decadal to million-year timescales. However interpretation of these changes is greatly compromised without a reliable chronology. Luminescence dating has not been used extensively in lacustrine settings; instead previous studies have often relied upon radiocarbon dating, using extrapolation beyond the upper limit of that technique, and employing opportunistic sampling of tephra and palaeomagnetic signatures where possible. This study from Lake Tana, Ethiopia, demonstrates that recent advances in luminescence methodology can provide long chronologies for lake sediments that are not dependent on the intermittent presence of dateable material, as is the case for radiocarbon and tephra-based methods. Specifically, this study generates luminescence ages that agree with independent chronology based on radiocarbon dating in the upper part of the core, and extends significantly beyond the range of radiocarbon dating to provide one of the longest independently dated lacustrine sediment records in eastern Africa, thus demonstrating the tremendous potential of luminescence for constructing lacustrine sediment chronologies over 100,000 year timescales

Keywords

  • palaeolimnology, luminescence dating, post-IR IRSL signal, plymineral fine-grains, lacustrine sediments, direct dating, OSL, radiocarbon