Integrating chronological uncertainties for annually laminated lake sediments using layer counting, independent chronologies and Bayesian age modelling (Lake Ohau, South Island, New Zealand)

Autor: Jocelyn Turnbull, Christopher Bronk Ramsey, Heidi A. Roop, Marcus J. Vandergoes, Xun Li, W. Troy Baisden, Christine Prior, Jamie Howarth, Liz D. Keller, Margaret Norris, Richard H. Levy, Gavin B. Dunbar, Sean J. Fitzsimons, Robert G. Ditchburn
Rok vydání: 2018
Předmět:
Zdroj: Quaternary Science Reviews. 188:104-120
ISSN: 0277-3791
Popis: Annually resolved (varved) lake sequences are important palaeoenvironmental archives as they offer a direct incremental dating technique for high-frequency reconstruction of environmental and climate change. Despite the importance of these records, establishing a robust chronology and quantifying its precision and accuracy (estimations of error) remains an essential but challenging component of their development. We outline an approach for building reliable independent chronologies, testing the accuracy of layer counts and integrating all chronological uncertainties to provide quantitative age and error estimates for varved lake sequences. The approach incorporates (1) layer counts and estimates of counting precision; (2) radiometric and biostratigrapic dating techniques to derive independent chronology; and (3) the application of Bayesian age modelling to produce an integrated age model. This approach is applied to a case study of an annually resolved sediment record from Lake Ohau, New Zealand. The most robust age model provides an average error of 72 years across the whole depth range. This represents a fractional uncertainty of ∼5%, higher than the
Databáze: OpenAIRE
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