TY - JOUR
T1 - Using Luminescence Dating to Constrain Lake Sediment Records
T2 - A New Age Model for the 1.38Ma Lake Malawi Drill Core, Eastern Africa
AU - Streib, Laura
AU - Armitage, Simon
AU - Scholz, Christopher
PY - 2024/6/15
Y1 - 2024/6/15
N2 - The 2005 Lake Malawi deep scientific drill core is the longest and most continuous high-resolution record from the continental tropics, extending to ~1.38 Ma. While extensive sets of paleoclimate proxy data have been generated from this core, a gap in directly dated sediment, between ~74 ka and ~590 ka (28-167 meters below lake floor), has limited the understanding of climatic drivers in this system. Previous age models fill the gap in direct dates by tuning to the global δ18O stack and interpreting paleomagnetic excursions, but these methods and the resulting models remain disputed. We fill this gap in chronology using luminescence dating, with 31 samples collected at ~4 m resolution in this section of the core. Luminescence dating can sometimes be limited by relatively large uncertainties (typically ~7%) and difficulty estimating the water content history of samples. We overcome these limitations by employing a high sampling density and using the sediment record to understand changes in water content during the burial period. This yields a vastly improved and robust age model that indicates changes in sedimentation rates not discernible in prior age models.
AB - The 2005 Lake Malawi deep scientific drill core is the longest and most continuous high-resolution record from the continental tropics, extending to ~1.38 Ma. While extensive sets of paleoclimate proxy data have been generated from this core, a gap in directly dated sediment, between ~74 ka and ~590 ka (28-167 meters below lake floor), has limited the understanding of climatic drivers in this system. Previous age models fill the gap in direct dates by tuning to the global δ18O stack and interpreting paleomagnetic excursions, but these methods and the resulting models remain disputed. We fill this gap in chronology using luminescence dating, with 31 samples collected at ~4 m resolution in this section of the core. Luminescence dating can sometimes be limited by relatively large uncertainties (typically ~7%) and difficulty estimating the water content history of samples. We overcome these limitations by employing a high sampling density and using the sediment record to understand changes in water content during the burial period. This yields a vastly improved and robust age model that indicates changes in sedimentation rates not discernible in prior age models.
U2 - 10.1016/j.quascirev.2024.108691
DO - 10.1016/j.quascirev.2024.108691
M3 - Article
SN - 0277-3791
VL - 334
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
M1 - 108691
ER -