This study identifies temporal biases in the radiocarbon ages of the planktonic foraminifera species Globigerina bulloides and Globigerinoides ruber (white) in a sediment core from the SW Iberian margin (so‐called Shackleton site). Leaching of the outer shell and measurement of the radiocarbon content of both the leachate and leached sample enabled us to identify surface contamination of the tests and its impact on their ¹⁴C ages. Incorporation of younger radiocarbon on the outer shell affected both species and had a larger impact downcore. Interspecies comparison of the ¹⁴C ages of the leached samples reveal systematic offsets with ¹⁴C ages for G. ruber being younger than G. bulloides ages during the last deglaciation and part of the Early and mid‐Holocene. The greatest offsets (up to 1,030 years) were found during Heinrich Stadial 1, the Younger Dryas, and part of the Holocene. The potential factors differentially affecting these two planktonic species were assessed by complementary ¹⁴C, oxygen and carbon isotopes, and species abundance determinations. The coupled effect of bioturbation with changes in the abundance of G. ruber is invoked to account for the large age offsets. Our results highlight that ¹⁴C ages of planktonic foraminifera might be largely compromised even in settings characterized by high sediment accumulation rates. Thus, a careful assessment of potential temporal biases must be performed prior to using ¹⁴C ages for paleoclimate investigations or radiocarbon calibrations (e.g., marine calibration curve Marine13, Reimer et al., 2013, https://doi.org/10.2458/azu_js_rc.55.16947).

中文翻译：

---

西伊比利亚边缘突发气候事件期间两种表层浮游有孔虫物种之间的放射性碳年龄抵消。

这项研究确定了伊比利亚西缘边缘（所谓的沙克尔顿遗址）沉积岩芯中浮游有孔虫物种Globigerina bulloides和Globigerinoides ruber （白色）的放射性碳年龄的时间偏差。对外壳的浸出以及对浸出液和浸出样品的放射性碳含量的测量使我们能够确定测试的表面污染及其对其¹⁴ C 年龄的影响。外壳上较年轻的放射性碳的掺入影响了这两个物种，并对地下产生了更大的影响。对浸出样品的¹⁴ C 年龄进行种间比较揭示了系统性偏移，在末次冰消期以及全新世早期和中期的部分时期，G. ruber的¹⁴ C 年龄比G. bulloides年轻。最大的偏移（长达 1,030 年）是在 Heinrich Stadial 1、新仙女木期和全新世的一部分期间发现的。^{通过互补14} C、氧和碳同位素以及物种丰度测定来评估对这两种浮游物种产生不同影响的潜在因素。生物扰动与G. ruber丰度变化的耦合效应被用来解释大的年龄偏移。我们的结果强调，即使在以高沉积物积累率为特征的环境中，浮游有孔虫的^{14 C 年龄也可能受到很大程度的损害。因此，在使用14} C 年龄进行古气候调查或放射性碳校准之前，必须对潜在的时间偏差进行仔细评估（例如，海洋校准曲线 Marine13，Reimer 等，2013，https://doi.org/10.2458/azu_js_rc .55.16947）。