Sedimentological and geochemical compositions of the Lake Petit sediments (Southern French Alps)

This dataset includes the sedimentological and geochemical analyses, that were used as proxies to reconstruct catchment and lake paleoenvironmental changes: - Age-depth model based on radiocarbon ages (7 samples) and short-lived isotopes (210Pb, 137Cs). - Clay-size particles abundance (Grain-size laser diffraction measured on a Malvern Mastersizer S at 5 mm sampling intervals). - Total organic carbon concentrations in per cent (24 discrete samples by Rock-Eval Pyrolysis on a Turbo Model RE6 pyrolyser), as well as Hydrogen and Oxygen Indexes (mg/g of total organic carbon). - Major element concentrations in per cent (SiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, TiO2, P2O5 measured by mass spectrometry on an ICP-AES Thermo X7 after LiBO2 alkaline fusion) and, biogenic silica (SiO2biog) concentration in per cent measured after wet-alkaline leaching using molybdate-yellow spectrophotometry on a Jasco V-650 Spectrophotometer. - Fourier Transformed Infrared Spectroscopy (FTIRS) inference for SiO2 biogenic and TOC concentrations in per cent (continuous sampling at 1 cm intervals), measured on a Nicolet 380 Smart Diffuse Reflectance spectrometer. - XRF core scanning inference for Detrital Fraction (DF% = 6.2*Ln[Ti/Si]+20.8), and Chemical Index of Alteration (Ln[Ti/Ca]); measure on an ITRAX Core Scanner (Mo source, 2 mm increment, integration time 60 s, energy 40 kV-35 mA).

As shown in Brisset et al., (2013), the relationship between the Ln(Ti/Ca) XRF intensities and the CIA (%) is linear and positive, and both are highly related (n = 20, r = 0.90).