In April 2012, cores were retrieved from the deepest part of Lake Muzelle using a UWITECH piston corer with hammer action. The master core sequence (MUZ12) is composed of two coring holes. MUZ1201 was retrieved from the lake bottom with a 90-mm-diameter tube, and MUZ1202 was retrieved with a 63-mm tube. A short gravity core, MUZ12P5, was also taken to provide a well-preserved sample of the water–sediment interface. In June 2014, a set of nine short gravity cores (MUZ14P1 to MUZ14P9) distributed across the deep portion of the lake basin were retrieved using a UWITECH piston corer, allowing us to better understand sediment partitioning throughout the entire lake system. All cores were split in half lengthwise. A detailed macroscopic description allowed to determine the different sedimentary facies and to establish the stratigraphic correlations between cores. A composite core was built using clearly identifiable layers in the overlapping sections of cores MUZ1201 and MUZ1202 to obtain a 283.5-cm-long sediment sequence. The chronology of the Lake Muzelle sediment sequence is

based on 10 14C measurements on terrestrial macroremains, short-lived radionuclide measurements, and paleomagnetic secular variations. The 14C measurements were carried out using accelerator mass spectrometry (AMS) methods.

Radioelements : Well type, low background gamma detector (Canberra) / Channels 8192 / Certified standards used for calbration curve (Energy and Efficiency) IAEA447 / Genie 2000 (version 3,3 Canberra)

210Pb, 137Cs, 241Am, 226Ra,7Be / 210Pb model : CFCS

The last century chronology was established with short-lived radio-isotopes (210Pb, 137Cs, 241Am) measured by gamma spectrometry in the underground laboratory of Modane (LSM-CNRS/CEA, France). Measurements were made on XXcm-thick samples of X to X g dried sediment, using a high efficiency, well-type Ge detector, during 24 to 72 h (deepest samples with lowest activities). The excess 210Pb (formed in the atmosphere by the decay of 222Rn) was calculated using 210Pb total activity corrected from 226Ra activity (supported 210Pb; Appleby, 2001). 210Pb chronology was derived using the (choose model CRS-CF/CS-CICR) Model