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.

本数据集涵盖2017年7—8月考察期间采集的勒拿河三角洲库龙纳赫岛更新世雅德玛冻土（Yedoma）的CO₂样品δ¹³C、F¹⁴C组成，以及相关沉积参数。
沉积物样品采用铁锹从活动层（active layer）土壤坑采集，采样点设于一处活跃后退式热融滑塌（retrogressive thaw slump）的三个区域：分别为完整冻胀丘（TM1、TM2）内的更新世雅德玛冻土、覆盖于该热融滑塌之上的全新世完整多边形苔原（HT1），以及因侵蚀作用导致更新世与全新世沉积物混合的热融滑塌坑底（SF3）。
研究人员采用呼吸室（respiration chambers）于三个采样点的活动层无植被区域原位（in-situ）采集CO₂样品，并对考察期间采集的沉积物样品开展为期1.5年的实验室培养实验，按固定间隔收集培养过程中产生的CO₂。本次分析旨在对比原位呼吸释放CO₂与实验室培养所得CO₂的碳同位素组成，进而明确释放CO₂的来源。