Impact of human activities and vegetation changes on the tetraether sources in Lake St Front (Massif Central, France)

•Downcore brGDGTs in Lake St Front sediments have a mixed origin.•ΣIIIa/ΣIIa ratio in the past can be used to reveal brGDGT source changes.•A gradual shift in brGDGT sources occurred during the Holocene in Lake St Front.•Shift in brGDGT sources results from changes in erosive dynamics of the catchment.•brGDGT distribution is impacted by vegetation changes and human activities.