Supplement of Biogeosciences, 17, 3797–3814, 2020 https://doi.org/10.5194/bg-17-3797-2020-supplement © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.

Supplement of Organic characteristics in ice-rich in alas and Yedoma deposits, central Yakutia,

Torben Windirsch et al.

Correspondence to: Torben Windirsch ([email protected])

The copyright of individual parts of the supplement might differ from the CC BY 4.0 License. © Google Earth

Figure S1 - Digital mapping of the Yukechi Alas landscape (red); lakes were digitalized in blue, Alas basins were digitalized in green; sampling locations Alas1 and YED1 marked in yellow; the 765 m distance between YED1 and Alas1 is marked by a red dotted line; satellite image: © Google Earth. (a) 500

1000

1500 depth [cm bs]

2000 20000 40000 60000 80000 100000 cal yr BP

(b) 500

1000

1500 depth [cm bs]

2000 20000 40000 60000 80000 100000 cal yr BP

Figure S2 - Age-depth model for YED1 (a) and Alas1 (b); radiocarbon ages in blue with uncertainties; median in red; model range indicated by grey dotted lines; created with the Bacon package in the R environment. -20 YED1 Alas1

-24 C [‰ vs. VPDB]

13 -28

-32 0 5 10 15 20 25 C/N ratio

Figure S3 - C/N values of YED1 (triangles) and Alas1 (dots) plotted over δ13C values. 0 100 YED1 Alas1

Clay 25 75

75 + Clay [%] - Sandy 20 Silty Clay Clay 50 50

+ Sand [%] -

Clayey Sand, Clayey

Sand Silt, Clay 20 Silt 75 25

75 20 Silty Sandy Sand Silt Sand Silt 100 75 0 Sand 0 25 50 75 100 Silt - Silt [%]-

Figure S4 - Sediment triangle after Shepard showing the grain size composition. Clay Silt Sand 10

grain size distribution 8 Y1 Y3 Y4

6

4 volume percent [%]

2

0 0.1 1 10 100 1000 grain size [µm]

Figure S5 - Grain size distribution for the YED1 core; Y1 to Y4 indicate the different stratigraphical units; core unit Y2 did not hold enough sediment. Clay Silt Sand 12

grain size distribution A1 A2 8 A3 A4

4 volume percent [%]

0 0.1 1 10 100 1000 grain size [µm]

Figure S6 - Grain size distribution for the Alas1 core; A1 to A4 mark the different stratigraphic units. Figure S7 - Photo of a large found on the Abalakh Terrace, Central Yakutia, approximately 30 km east of the Yukechi Alas landscape; photo by Mathias Ulrich.