Radiocarbon dates on marine shell and other materials of marine origin appear significantly older than contemporaneous samples of terrestrial/atmospheric origin. Misunderstandings regarding the mechanisms that give rise to this “marine reservoir effect” (MRE), the terminology used to define it, and the mathematics used to describe it cause many coastal archaeologists to distrust or misinterpret marine shell dates. The recent release of a reformulated 14C calibration curve for marine samples (Marine20), which necessitates recalculation of all local reservoir age corrections, may add to the confusion. Here, we review the benefits of dating shell; provide a plain-language explanation of the mechanical, chemical, biological, and cultural processes that give rise to age disparities associated with the MRE; and offer advice to archaeologists intending to date marine shell. Our hope is that these comments will not only aid archaeologists in the planning and interpretive stages of research but also assist in assessing the reliability of legacy chronologies based on marine materials. More broadly, we encourage careful evaluation of all sources of uncertainty in all 14C chronologies, whether based on terrestrial or marine materials.

海洋贝壳和其他海洋来源材料的放射性碳日期似乎比同时期的陆地/大气来源样本要早得多。对产生这种“海洋水库效应”(MRE) 的机制、用于定义它的术语以及用于描述它的数学的误解导致许多沿海考古学家不信任或误解海洋贝壳年代。最近发布的重新配制的14海洋样品 (Marine20) 的 C 校准曲线需要重新计算所有当地水库年龄校正，这可能会增加混乱。在这里，我们回顾了 dating shell 的好处；对导致与 MRE 相关的年龄差异的机械、化学、生物和文化过程提供通俗易懂的解释；并向打算确定海洋贝壳年代的考古学家提供建议。我们希望这些评论不仅能在研究的规划和解释阶段帮助考古学家，还能帮助评估基于海洋材料的遗留年代学的可靠性。更广泛地说，我们鼓励仔细评估所有14 C 年表中的所有不确定性来源，无论是基于陆地还是海洋材料。