No CrossRef data available.
Published online by Cambridge University Press: 16 October 2025
We used AMS 14C dating to determine the age of the composite wedge formation in the Batagay Upper Sand unit. The composite wedges are interpreted as syngenetic structures; they have grown vertically upward with aggradation of the host sandy deposits. The formation of composite wedges in Upper Sand commenced no later than 38.3 cal ka BP and stopped not earlier than 25.5 cal ka BP in the northwestern part of the slump. In the formation of ice wedges within the Upper Sand, frost cracks extended to a depth of 5–7 m, surpassing the normal depth of 3–4 m observed in the Upper Ice Complex. The composite ice wedges in the Upper Sand formed at temperatures ranging from –47 to –54°C, as evidenced by the paleotemperature reconstruction of the isotope composition of the Upper Ice Complex’s ice wedges.