Teshekpuk Lake stands out on the Alaskan North Slope as the largest thermokarst lake in the world. To our knowledge, no comprehensive sediment core datasets directly from the lake have been published to date, unlike to most of the neighbouring smaller lakes. During a pilot study, one sediment core taken on an expedition in 2022 on the northern coast of Teshekpuk Lake, was analysed for basic sedimentological and geochemical parameters, including magnetic susceptibility, total (organic) carbon, nitrogen and mercury. Further analysis for grain size, δ13C and dating is in progress, as well as an expansion of the study area to one neighbouring lake (Peatball lake). First results of the Teshekpuk Lake core showed a thick sandy sediment layer with very low total organic carbon (TOC), total nitrogen (TN) and total mercury (THg) contents. The typical peat layer lies further down in contrast to most other local thermokarst lakes. This opens a discussion about the origin of these sandy sediments to which there are multiple theories.