In high-mountain areas, Pleistocene glaciations and erosion-related processes erased most of the pre-existing landforms and soils. However, on scattered stable surfaces, ancient soils can be locally preserved for long periods, retaining valuable palaeoenvironmental information. Such relict surfaces survived during glaciations either through coverage by non-erosive, cold-based, ice or as nunataks. Thus, soils preserved on such surfaces retain an excellent pedo-signature of different specific past climatic/environmental conditions. In this study, we performed a detailed chemical characterisation of the organic material found in palaeosols, discovered inside periglacial features on a high-elevation Lateglacial Alpine Nunatak (Stolenberg Plateau), above 3000 m a.s.l. (NW Italian Alps). The soil organic matter (OM) was separated into different pools by means of density fractionation, in order to separate the more fresh/unaltered free and occluded organic material (Light Fraction) from the stable fraction chemically bound to the mineral phase (Mineral Organic Matter—MOM). To better characterise the MOM fraction, this was further subjected to chemical fractionation, in order to separate the alkali-extractable OM (ext-MOM) from the fraction intimately bound to minerals. The obtained fractions were then characterised by chemical and ¹³C nuclear magnetic resonance (NMR), and Fourier Transform Infrared (FT-IR) spectroscopy. The results indicated that the largest part (>90%) of organic carbon was stored in the stable MOM pool, characterised by a high degree of decomposition and consisting mainly of paraffinic substances, such as lipids and waxes (37–50%), cellulose and hemicellulose (29–37%). The OM likely originated from autochthonous, well-adapted, ancient alpine vegetation (alpine tundra) that grew on the Plateau during warm climatic phases since the end of the Last Glacial Maximum (LGM). These results further strengthen the palaeoenvironmental reconstruction at the Stolenberg Plateau, which represents a Lateglacial Alpine Nunatak, and has acted as biological refugia (at least) since the end of the LGM.

中文翻译：

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高海拔晚冰川阿尔卑斯努纳塔克（意大利西北部）古代有机物的起源和特征

在高山地区，更新世的冰川作用和与侵蚀相关的过程抹去了大部分原有的地貌和土壤。然而，在分散的稳定表面上，古土壤可以在局部长期保存，保留着宝贵的古环境信息。这些遗迹表面在冰川作用期间通过非侵蚀性、冷基、冰或作为努纳塔克的覆盖而幸存下来。因此，保存在这些表面上的土壤保留了过去不同特定气候/环境条件的优良土壤特征。在这项研究中，我们对古土壤中发现的有机物质进行了详细的化学表征，这些有机物质是在海拔 3000 米以上（NW 意大利阿尔卑斯山）的高海拔晚冰期阿尔卑斯努纳塔克山（斯托伦贝格高原）的冰缘特征内部发现的。通过密度分级将土壤有机质 (OM) 分离到不同的池中，以便从化学结合到矿物相的稳定部分（矿物有机质）中分离出更新鲜/未改变的游离和吸留有机物质（轻质部分） -妈妈）。为了更好地表征 MOM 分数，将其进一步进行化学分馏，以便将碱可提取的 OM (ext-MOM) 从与矿物质密切结合的分数中分离出来。获得的级分然后通过化学和 将其进一步进行化学分馏，以便将碱可提取的 OM (ext-MOM) 从与矿物质紧密结合的部分中分离出来。获得的级分然后通过化学和 将其进一步进行化学分馏，以便将碱可提取的 OM (ext-MOM) 从与矿物质紧密结合的部分中分离出来。获得的级分然后通过化学和¹³ C核磁共振（NMR）和傅里叶变换红外（FT-IR）光谱。结果表明，最大部分 (>90%) 的有机碳储存在稳定的 MOM 库中，其特点是高度分解，主要由石蜡物质组成，如脂质和蜡 (37-50%)、纤维素和半纤维素 (29–37%)。OM 可能起源于自末次盛冰期 (LGM) 结束以来在温暖气候阶段在高原上生长的本土、适应性强的古老高山植被（高山苔原）。这些结果进一步加强了斯托伦贝格高原的古环境重建，它代表了晚冰期高山努纳塔克，并且自 LGM 结束以来（至少）一直充当生物避难所。