Data for: Sources of CO2 produced in freshly thawed Pleistocene-age Yedoma permafrost

This dataset contains δ13C and F14C compositions of CO2 samples as well as sedimentary parameters from Pleistocene Yedoma located on Kurungnakh Island in the Lena River Delta, collected during an expedition in July/August 2017.

Sediment samples were collected from active layer soil pits, using shovels, at three sites on an active retrogressive thaw slump: Pleistocene-aged Yedoma from intact thaw mounds (TM1, TM2), intact Holocene polygonal tundra overlaying the thaw slump (HT1) and sediments from the thaw slump floor (SF3), where Pleistocene and Holocene sediments mix as a result of erosion.

CO2 was collected in-situ from the three sites using respiration chambers, set up on vegetation-free spots on the active layer and, in fixed intervals, from a 1.5-year laboratory incubation experiment of sediment samples collected during the expedition. The analyses were performed to compare the C-isotopy of in-situ respired CO2 with that of CO2 produced during the incubation and to determine the sources of the released CO2.