Evidence for millennial-scale interactions between Hg cycling and hydroclimate from Lake Bosumtwi, Ghana

Paine, Alice R.; Frieling, Joost; Shanahan, Timothy M.; Mather, Tamsin A.; McKay, Nicholas; Robinson, Stuart A.; Pyle, David M.; Fendley, Isabel M.; Kiely, Ruth; Gosling, William D.

doi:https://doi.org/10.5194/cp-21-817-2025

Articles | Volume 21, issue 4

https://doi.org/10.5194/cp-21-817-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/cp-21-817-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 21, issue 4

Research article

|

17 Apr 2025

Research article |

| 17 Apr 2025

Evidence for millennial-scale interactions between Hg cycling and hydroclimate from Lake Bosumtwi, Ghana

Alice R. Paine, Joost Frieling, Timothy M. Shanahan, Tamsin A. Mather, Nicholas McKay, Stuart A. Robinson, David M. Pyle, Isabel M. Fendley, Ruth Kiely, and William D. Gosling

Supplement

https://doi.org/10.5194/cp-21-817-2025-supplement

Data sets

Age and smoothed natural gamma ray (NGR) data from core GLAD6 BOS04 5B Mathias Vinnepand et al. https://doi.org/10.1594/PANGAEA.969451

The time-transgressive termination of the African humid period (https://www.ncei.noaa.gov/access/paleo-search/study/18355) Timothy M. Shanahan et al. https://doi.org/10.1038/ngeo2329

A magnetic mineral record of Late Quaternary tropical climate variability from Lake Bosumtwi, Ghana (https://www.ncei.noaa.gov/access/paleo-search/study/5454) J. A. Peck et al. https://doi.org/10.1016/j.palaeo.2004.08.003

Short summary

Few tropical mercury (Hg) records extend beyond ~ 12 ka, meaning our current understanding of Hg behaviour may not fully account for the impact of long-term hydroclimate changes on the Hg cycle in these environments. Here, we present an ~ 96 kyr Hg record from Lake Bosumtwi, Ghana. A coupled response is observed between Hg flux and shifts in sediment composition reflective of changes in lake level, suggesting that hydroclimate may be a key driver of tropical Hg cycling over millennial timescales.