Our understanding of past ocean-climate dynamics is informed by multiple paleocirculation proxies including δ¹³C, ²³¹Pa/²³⁰Th, and radiogenic neodymium isotopes (ε_Nd). Of these, the ε_Nd signature of marine authigenic phases is of particular importance as it is considered a robust circulation proxy applicable across timescales, permitting circulation reconstructions during periods of rapid, climatically-induced biological or chemical change (e.g. productivity, pH). However, growing evidence of non-conservative behavior and a widespread sedimentary source (benthic flux via pore water) of Nd to the global ocean suggests that authigenic ε_Nd records do not strictly record a water mass signature, highlighting the need to reconsider interpretations of the authigenic record. To examine the impact of a sedimentary influence on the authigenic record, here we compile paired authigenic and detrital neodymium records from every major ocean basin and from 80 Ma to present. We then focus on just the North Atlantic Ocean basin to examine if this relationship holds up regionally and how authigenic ε_Nd changes relate to sediment composition changes from two scientific ocean drill cores spanning the past 25 ka. We present a new conceptual framework to guide our discussion that examines the coupling or decoupling of authigenic and detrital ε_Nd in terms of the relative importance of each of the three major potential controls on the authigenic record as defined in the existing literature (bottom water, pore water, sediments). Our compilation reveals a strong linear relationship between detrital ε_Nd and authigenic ε_Nd (correlation coefficient = 0.86, n=871), demonstrating a widespread influence of lithogenically sourced neodymium on authigenic ε_Nd. We find the same is true within the North Atlantic, with the authigenic records at both locations strongly influenced by the sediments and not likely recording bottom water neodymium values. Emerging evidence for a lithogenic or benthic flux influence on the budgets of a wide range of trace elements suggests that our interpretative framework will be broadly useful for understanding the behavior of trace elements and their isotopes at the sediment-water interface.

我们对过去海洋气候动力学的理解是由多种古环流代理提供的，包括 δ ¹³ C、²³¹ Pa/ ²³⁰ Th 和放射性钕同位素 (ε _Nd )。其中，海洋自生阶段的 ε _Nd特征特别重要，因为它被认为是适用于跨时间尺度的强大循环代理，允许在快速、气候引起的生物或化学变化（例如生产力、pH 值）期间重建循环。然而，越来越多的证据表明 Nd 向全球海洋的非保守行为和广泛的沉积源（通过孔隙水的底栖通量）表明自生 ε _Nd记录并未严格记录水团特征，突出表明需要重新考虑对自生记录的解释。为了检查沉积影响对自生记录的影响，我们在这里汇编了来自每个主要海洋盆地和从 80 Ma 到现在的成对的自生和碎屑钕记录。然后，我们只关注北大西洋盆地，以检查这种关系在区域上是否成立，以及自生 ε _Nd变化如何与跨越过去 25 ka 的两个科学海洋钻探岩心的沉积物成分变化相关。我们提出了一个新的概念框架来指导我们的讨论，该框架检查自生和碎屑 ε _Nd的耦合或解耦就现有文献（底水、孔隙水、沉积物）中定义的自生记录的三个主要潜在控制因素中的每一个的相对重要性而言。我们的汇编揭示了碎屑 ε _Nd和自生 ε _Nd之间的强线性关系（相关系数 = 0.86，n = 871），证明了岩性来源的钕对自生 ε _Nd的广泛影响. 我们发现在北大西洋也是如此，两个位置的自生记录都受到沉积物的强烈影响，不太可能记录底水的钕值。岩石成因或底栖通量对各种微量元素收支影响的新证据表明，我们的解释框架将广泛用于理解沉积物-水界面处微量元素及其同位素的行为。