Two cores from a Weichselian periglacial alluvial fan were dated using ¹⁴C and OSL, to verify the reliability of both methods and check the upper dating limit of the ¹⁴C method. Both dating methods yielded a similar chronology for core Eerbeek-I, with infinite ¹⁴C dates for the lower part where OSL dates indicated ages of over 45 ka. Finite ¹⁴C dates were obtained throughout the core for Eerbeek-II, despite stratigraphic and OSL evidence suggesting ages beyond ¹⁴C limits. Apparently, additional chemical pre-treatment to remove younger carbon fractions did not work adequately for samples from this core. We hypothesize that this may be related to a larger influence of younger-age humin fractions in the mainly sandy Eerbeek-II deposits compared to those buffered by a thick peat layer of Eerbeek-I. We suggest that (local) stratigraphy, percolation and humification processes may impact ¹⁴C ages of organic deposits more than commonly assumed, and should receive more attention. In addition, we introduce a new method to assess robustness and validity of OSL dates and demonstrate the applicability of OSL dating methods in this setting. Our results highlight that the ¹⁴C method requires additional verification methods, such as OSL, for deposits older than 30 ka.

用¹⁴ C和OSL对Weichselian沿冰川冲积扇的两个岩心进行了测年，以验证这两种方法的可靠性并检查¹⁴ C方法的测年上限。两种测年方法都为核心Eerbeek-I产生了类似的年代顺序，下部的无穷大¹⁴ C日期，OSL日期表明年龄超过45 ka。尽管地层和OSL证据表明年龄超过¹⁴岁，但在Eerbeek-II的整个岩心中都获得了有限的¹⁴ C日期C限制。显然，额外的化学预处理以去除较年轻的碳馏分不适用于该岩心中的样品。我们假设，这可能与主要由沙质的Eerbeek-II矿床形成的较年轻的人的腐殖质组分比由Eerbeek-I的较厚泥炭层所缓冲的更大的影响有关。我们建议，（当地）地层，渗流和增湿作用可能比通常认为的对有机沉积物¹⁴ C年龄的影响更大，因此应引起更多关注。此外，我们引入了一种新的方法来评估OSL日期的鲁棒性和有效性，并证明OSL日期方法在此环境中的适用性。我们的结果强调了¹⁴对于超过30 ka的矿床，C方法需要其他验证方法，例如OSL。