Fine-scale temporal processes, such as the synchronous deposition of organic materials, can be challenging to identify using 14C datasets. While some events, such as volcanic eruptions, leave clear evidence for synchronous deposition, synchroneity is more difficult to establish for other types of events. This has been a source of controversy regarding 14C dates associated with a hypothesized extraterrestrial impact at the Younger Dryas Boundary (YDB). To address this controversy, we first aggregate 14C measurements from Northern Hemisphere YDB sites. We also aggregate 14C measurements associated with a known synchronous event, the Laacher See volcanic eruption. We then use a Monte Carlo simulation to evaluate the magnitude of variability expected in a 14C dataset associated with a synchronous event. The simulation accounts for measurement error, calibration uncertainty, “old wood” effects, and laboratory measurement biases. The Laacher See 14C dataset is consistent with expectations of synchroneity generated by the simulation. However, the YDB 14C dataset is inconsistent with the simulated expectations for synchroneity. These results suggest that a central requirement of the Younger Dryas Impact Hypothesis, synchronous global deposition of a YDB layer, is extremely unlikely, calling into question the Younger Dryas Impact Hypothesis more generally.

中文翻译：

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放射性碳模拟无法支持新仙女木撞击假说的时间同步性要求

精细的时间过程，例如有机材料的同步沉积，可能难以识别使用14C 数据集。虽然一些事件，如火山爆发，为同步沉积留下了明确的证据，但其他类型的事件更难建立同步性。这一直是争议的根源14C 日期与新仙女木边界 (YDB) 的假设外星撞击有关。为了解决这个争议，我们首先汇总14来自北半球 YDB 站点的 C 测量值。我们也聚合14与已知的同步事件 Laacher See 火山喷发相关的 C 测量值。然后，我们使用蒙特卡罗模拟来评估预期的变化幅度14与同步事件关联的 C 数据集。模拟考虑了测量误差、校准不确定性、“老木头”效应和实验室测量偏差。拉赫见14C 数据集与模拟生成的同步性预期一致。然而，YDB14C 数据集与模拟的同步预期不一致。这些结果表明，Younger Dryas 撞击假说的核心要求，即 YDB 层的同步全球沉积是极不可能的，这对更普遍的 Younger Dryas 撞击假说提出了质疑。