Northwest African Sahel climate variations during Holocene/Late Pleistocene: Insights from plant wax stable hydrogen (dD) and carbon (d13C) isotopic composition and sea-surface temperature

Abstract

This study investigates the last 44 kyr of Late Quaternary changes in West African monsoon intensity and vegetation, and their potential link to Atlantic meridional overturning circulation and sea-surface temperatures of the adjacent ocean. Analyses were done using marine cores retrieved from the continental slope off the coast of Senegal. Changes in West African monsoon intensity and vegetation (that is C3 vs. C4 plants) were estimated using Deuterium/Hydrogen ratios (dD) and the stable carbon isotopic composition (d13C) of individual plant wax n-alkanes. Deepwater ventilation at the study site was assessed through d13C of tests from benthic foraminifera and sea-surface temperatures were estimated using alkenone-paleothermometry based on the UK'37 index.