Bulk geochemical data and fractional abundances of brGDGTs and brGMGTs in soils, SPM and sediments in the Seine River basin (NW France)

This dataset includes elemental and isotopic data, environmental parameters, and fractional abundances of branched glycerol dialkyl glycerol tetraethers (brGDGTs) and branched glycerol monoalkyl glycerol tetraethers (brGMGTs) in the soils, Suspended Particulate Matter (SPM), and sediments collected along the Seine River basin in Northwest France. Samples (n=237) were collected in high-flow (over 250 m³/s) and low-flow (below 250 m³/s) periods from the three zones (river, upstream estuary and downstream estuary) of the Seine River basin from 2015 to 2021. Elemental and isotopic analyses were performed by an elemental analyzer coupled with an isotope ratio mass spectrometer. The brGDGTs and brGMGTs were analyzed using high pressure liquid chromatography coupled with mass spectrometry with an atmospheric pressure chemical ionization source in selected ion monitoring mode. Using this dataset, we aim to (1) investigate the sources of brGDGTs and brGMGTs along the land-sea continuum, (2) identify the environmental factors influencing the distribution of these molecules, and (3) evaluate the applicability of brGMGTs as an indicator for riverine runoff.