Abstract Last Glacial Maximum and Holocene environmental conditions are reconstructed from a lacustrine core obtained from Lake Arturo, located in the Fuegian steppe of southern Argentina. Proxies include diatoms, ostracods, plants remains, organic matter content and sedimentological studies, and they suggest that Lake Arturo experienced climate-related variations in the water level, hydrological balance and temporal stability throughout the last 23,200 cal yr BP. The Late Glacial period, which ended about 15,400 cal yr BP, is characterized by a few low-diversity diatom assemblages dominated by benthic and small-celled fragilarioid taxa. Between the Pleistocene-Holocene transition and the mid-Holocene, Lake Arturo was a shallow, fresh-to-brackish lake with relatively high organic productivity. Around 6200 cal yr BP, the diatom Surirella tuberosa replaced Thalassiosira patagonica, and diatom species richness fell to its lowest level in the records. Together with the presence of the ostracod Limnocythere rionegroensis, which lives in ephemeral environments, this suggests that the lake was very shallow and experienced negative hydrological balance, with hydrochemical and biological conditions that were similar to those of today. Data from other sites in southern Tierra de Fuego suggest that, around 5000 cal yr BP until 800 cal yr BP the rainfall increased and the temperature decreased as a result of an intensification of the Southern Westerlies. By that time, the Lake Arturo record indicates the existence of an ephemeral, shallow, highly saline water body. This suggests an antiphase response to the atmospheric circulation pattern between the southern humid forest and the northern steppe during the middle to late Holocene.

中文翻译：

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晚冰期和全新世气候变化的古湖泊学响应：来自阿根廷南部 Fuegian 草原的阿图罗湖的记录

摘要 末次盛冰期和全新世环境条件是从位于阿根廷南部 Fuegian 草原的阿图罗湖 (Lake Arturo) 获得的湖相核心重建的。替代物包括硅藻、介形动物、植物遗骸、有机质含量和沉积学研究，它们表明阿图罗湖在过去 23,200 cal BP 期间经历了与气候相关的水位、水文平衡和时间稳定性变化。晚冰期结束了大约 15,400 cal yr BP，其特征是一些低多样性的硅藻组合，以底栖和小细胞脆性类群为主。在更新世-全新世过渡期和中全新世之间，阿图罗湖是一个浅水、淡水到咸水湖，有机生产力相对较高。大约 6200 cal yr BP，硅藻 Surirella tuberosa 取代了 Thalassiosira patagonica，硅藻物种丰富度降至有记录以来的最低水平。再加上生活在短暂环境中的介形动物 Limnocythere rionegroensis 的存在，这表明该湖非常浅，经历了负水文平衡，水化学和生物条件与今天相似。来自火地岛南部其他地点的数据表明，大约 5000 cal yr BP 到 800 cal yr BP，由于南部西风带的加强，降雨量增加，温度降低。到那时，阿图罗湖的记录表明存在一个短暂的、浅的、高盐度的水体。