Mollusc biogenic carbonates are valuable records of past environmental conditions. In particular, carbonate oxygen (δ¹⁸O) and carbon (δ¹³C) stable isotopes can be used to reconstruct different physical and chemical parameters, according to the different genera used (marine, freshwater or terrestrial). The Last Interglacial (early Eemian) palaeolake of Neumark‐Nord 2 (NN2), Germany provides an excellent example of a Neanderthal archaeological site with abundant freshwater carbonate remains. As in other European contexts, one of the most abundant species is Bithynia tentaculata. In order to provide a robust regional baseline for the interpretation of the archaeological data, this study includes a calibration phase on modern B. tentaculata opercula. The results indicate that these calcitic structures are likely to be subjected to a growth slowdown/cessation during summer, which influences their geochemistry, reflecting mainly the water properties of the rest of the year. This modern calibration, together with the existing palaeoenvironmental reconstructions developed for NN2 (e.g. pollen data), represents a valuable opportunity to establish B. tentaculata opercula as reliable environmental proxies applicable to several other freshwater contexts. The isotope data of the NN2 opercula, in agreement with the pollen record, indicate that the major archaeological horizon was formed during a rather wet period and potentially in a semi‐forested environment. However, human occupation occurred also during drier phases at the site and within a wide temperature range, indicating the absence of restricted environmental preferences by the local Neanderthal groups.

中文翻译：

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根据对淡水软体动物的稳定同位素分析推断，德国最后一个冰间期（Eemian）站点Neumark-Nord 2的环境条件

软体动物生物碳酸盐是过去环境条件的宝贵记录。特别地，碳酸氧（δ ¹⁸ O）和碳（δ ¹³ C）稳定同位素可用于重建不同的物理和化学参数，根据所使用的不同的属（海洋，淡水或陆地）。德国Neumark-Nord 2（NN2）的最后一个冰川间期（Eemian早期）古湖提供了一个尼安德特人考古遗址的实例，该遗址具有丰富的淡水碳酸盐残留物。与欧洲其他地区一样，最丰富的物种之一是Bithynia tentaculata。为了为解释考古数据提供可靠的区域基线，本研究包括对现代B. tentaculata的校准阶段oper 结果表明，这些钙质结构在夏季可能会经历生长减慢/停止，这影响了它们的地球化学，主要反映了该年剩余时间的水质。这种现代的标定方法，以及为NN2开发的现有古环境重构（例如花粉数据），为建立B. tentaculata提供了宝贵的机会。opercula作为适用于其他几种淡水环境的可靠环境代理。与花粉记录一致，NN2的同位素数据表明，主要的考古视野是在相当潮湿的时期形成的，并且可能在半森林环境中形成。但是，在该地点较干燥的阶段以及较宽的温度范围内也发生了人类占领，这表明当地的尼安德特人群体没有受到限制的环境偏好。