Abstract We present a revised varve chronology for the duration of ice-dammed lakes that formed in the Lochaber district, Scotland, during the Loch Lomond (‘Younger Dryas’) Stadial. We analysed new varved sequences and combined them with existing varve records to develop the Lochaber Master Varve Chronology 2019 (LMVC19), published here for the first time. It spans an interval of 518 ± 18 vyrs and is considered more secure than its predecessors because: (i) it is anchored by a more robust record of the Vedde Ash, which is dated to 12,043 ± 43 cal yr BP; and (ii) it provides revised estimates of the timings of key regional palaeoclimatic shifts that are fully compatible with those inferred from independently-dated, non-varved records obtained from neighbouring sites. The new results indicate that the Lochaber ice-dammed lakes existed between ∼12,135 and 11,618 ± 61 cal yr BP, but the pattern of glacier advance that led to lake formation was more complex than previously assumed, with some ice fronts reaching their maximal positions 300 years before others. Initiation of ice retreat at ∼11,800 cal yr BP appears to have coincided with a rise of ∼2 °C in mean July temperatures inferred from chironomid data obtained from the Abernethy Forest site in the eastern Highlands. This local climatic shift is thought to have been a delayed response (by up to 335 years) to a mid-Stadial northward migration of the North Atlantic Polar Front, the delay probably due to the influence of the SW Highland icefield. Subsequent retreat that led to the formation of ice stagnation features throughout large parts of the area was initiated by a further rise in summer air temperature of ∼3 °C at the start of the Early Holocene. Final drainage of the lake system occurred ∼190 years after the initiation of ice retreat, while it took a further 200 years for the ice to vacate the Rannoch plateau, a nearby upland glacial source.

中文翻译：

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苏格兰 Lochaber 地区 Loch Lomond Readvance（'Younger Dryas'）冰瓣生长和消亡的修订年表

摘要 我们提出了在洛蒙德湖（'年轻的仙女座'）体育场期间在苏格兰洛哈伯区形成的冰坝湖泊持续时间的修订版本年表。我们分析了新的 varved 序列并将它们与现有的 varve 记录相结合，以开发 Lochaber Master Varve Chronology 2019 (LMVC19)，首次在此处发布。它跨越 518 ± 18 vyrs 的间隔，被认为比其前辈更安全，因为：(i) 它以更可靠的 Vedde Ash 记录为基础，该记录可追溯到 12,043 ± 43 cal yr BP；(ii) 它提供了对关键区域古气候变化时间的修正估计，这些估计与从邻近地点获得的独立日期、无变种记录推断的那些完全一致。新的结果表明 Lochaber 冰坝湖泊存在于 ∼12, 135 和 11,618 ± 61 cal yr BP，但导致湖泊形成的冰川推进模式比以前假设的更复杂，一些冰锋比其他冰锋提前 300 年到达最大位置。大约 11,800 cal BP 开始的冰退缩似乎与从东部高地 Abernethy Forest 站点获得的摇蚊数据推断出的 7 月平均温度升高 2 °C 相吻合。这种局部气候变化被认为是对北大西洋极地锋中期 Stadial 向北迁移的延迟响应（最多 335 年），延迟可能是由于西南高地冰原的影响。随后的退缩导致该地区大部分地区形成冰滞特征，这是由早全新世开始时夏季气温进一步升高约 3 °C 引发的。湖泊系统的最终排水发生在冰开始退缩后约 190 年，而冰又花了 200 年才离开附近的高地冰川源兰诺克高原。