The proxy data reported here are measured from a sediment core collected from Lake Sardarya (28° 38' 03" N, 61° 00' 44" E, 2675 m a.s.l.) situated on the western slope of Taftan volcano, southeastern Iran. The core is 550 cm long and was collected in May 2017. For carbon-nitrogen-sulfur measurement, two sets of 28 samples from the Sardarya sediment core were collected, dried in a drying cabinet at 50 °C for 48 hours and ground and homogenized using mortar and pestle. One set of samples was weighed into tin capsules and analysed without further pretreatments. The other set of samples was pretreated with 3% and 20% hydrochloric acid (HCl) overnight at a temperature of 80 °C to remove carbonates and weighed into silver capsules. Finally, these samples were also analyzed with a Euro-EA Elemental Analyzer at the GEOPOLAR lab (Institute of Geography, University of Bremen) providing weight percentages of total organic carbon (TOC). Carbon to nitrogen ratio (C/N) was calculated by dividing TOC with total nitrogen (TN).

Carbon-Nitrogen-Sulfur measurements: 28 samples, measured at the GEOPOLAR lab (Institute of Geography, University of Bremen) (20.09.2017)