Isoprenoidal glycerol dialkyl glycerol tetraethers (isoGDGTs) are archaeal biomarkers. In many settings, the degree of cyclization of isoGDGTs is correlated with temperature, forming the basis of the TEX₈₆ paleothermometer that is widely used to reconstruct sea surface temperature (SST) across a range of time scales. However, the application of TEX₈₆ to the polar regions is relatively limited and there is currently no consensus on which calibration is best suited for polar environments. In addition, application of TEX₈₆ to the polar regions is complicated by uncertainty regarding the source of organic matter input in coastal polar environments. We tested five different calibrations for TEX₈₆ in marine sediments from the Antarctic coastal region of Admiralty Bay near King George Island, using four short cores that span the second half of the 20th century. We also explored the possible sources of organic matter in these cores using sterol biomarkers. Best results for TEX₈₆ were obtained using a quadratic calibration. The TEX₈₆ signal presented a strong seasonal signal and best matched reanalysis temperatures of the austral spring season (Oct-Nov-Dec). The most abundant compounds observed in the sediments were the sterols cholest-5-en-3β-ol and 24-ethylcholest-5-en-3β-ol, the fatty alcohols C₁₆ and phytol, and isoGDGT-0, indicating a dominant marine origin of the organic matter. Differences in their vertical distributions suggests that some compounds (such as cholest-5-en-3β-ol and phytol) may have had different sources over the evaluated period. Together our results indicate that TEX₈₆ can be used to reconstruct SSTs in the Antarctic coastal region.

类异戊二烯甘油二烷基甘油四醚 (isoGDGT) 是古细菌生物标志物。在许多情况下，isoGDGT 的环化程度与温度相关，构成了 TEX ₈₆古温度计的基础，该古温度计广泛用于重建一系列时间尺度的海面温度 (SST)。然而，TEX ₈₆在极地地区的应用相对有限，目前还没有就哪种校准最适合极地环境达成共识。此外，由于沿海极地环境中有机物质输入来源的不确定性，将TEX ₈₆应用于极地地区变得复杂。我们为 TEX ₈₆测试了五种不同的校准在来自乔治王岛附近金钟湾南极沿海地区的海洋沉积物中，使用跨越 20 世纪下半叶的四个短岩心。我们还使用甾醇生物标志物探索了这些岩心中有机物的可能来源。TEX _{86 的}最佳结果是使用二次校准获得的。TEX ₈₆信号呈现出强烈的季节性信号和最匹配的南方春季（10 月至 11 月至 12 月）的再分析温度。在沉积物中观察到的最丰富的化合物是甾醇 cholest-5-en-3β-ol 和 24-ethylcholest-5-en-3β-ol，脂肪醇 C ₁₆和植醇以及isoGDGT-0，表明有机质的主要海洋来源。其垂直分布的差异表明，某些化合物（如 cholest-5-en-3β-ol 和植醇）在评估期间可能具有不同的来源。我们的结果共同表明，TEX ₈₆可用于重建南极沿海地区的 SST。