Chromium (Cr) has shown promise as a paleoceanographic proxy due to the redox-driven control of dissolved Cr concentrations ([Cr]) and stable isotope composition (${\delta }^{53}$Cr). To improve the mechanistic understanding of Cr cycling in the modern ocean and strengthen its potential proxy applications, we present new data from regeneration incubations, bottom and sediment pore waters, and a compilation of intermediate and deep water data. While Cr removal and biological export from the surface ocean is associated with organic carbon export, the deep water release of dissolved Cr from sinking particles is not directly dependent on organic carbon respiration, as indicated by differing trends between Cr, oxygen utilization and the regeneration of organic-associated macronutrients (e.g. N, P). Pore water and bottom water data demonstrate that benthic Cr fluxes are locally important and may be significant globally. The pore water dissolved Cr flux at our CaCO₃-rich site is likely driven by the re-release of Cr scavenged from the water column by sinking particles, with minor contributions from lithogenic phases. We argue this is consistent with the highest open ocean [Cr] to date being found in the water column below oxygen minimum zones, likely reflecting the release of scavenged Cr in deep waters or surface sediments. Chromium released from suspended particles and surface sediments follows the global ${\delta }^{53}$Cr–[Cr] array, supporting the proposed role of biological export and regeneration in shaping global Cr and ${\delta }^{53}$Cr distributions. Global intermediate and deep water [Cr], ${\delta }^{53}$Cr and Cr:macronutrient relationships are thus shaped by a synergy of circulation patterns, water mass mixing, a deep Cr regeneration cycle, and benthic Cr sources. A biogenic control on global Cr distributions indicates that sedimentary Cr records may reflect biogenic as well as O₂-dependent processes, while more research is needed to assess sediment Cr record fidelity based on an active diagenetic cycle.

由于氧化还原驱动控制溶解的 Cr 浓度 ([Cr]) 和稳定的同位素组成，铬 (Cr) 已显示出作为古海洋学代理的前景。${\delta }^{53}$铬）。为了提高对现代海洋中 Cr 循环的机理理解并加强其潜在的代理应用，我们提供了来自再生孵化、底部和沉积物孔隙水的新数据，以及中深水数据的汇编。虽然表层海洋的 Cr 去除和生物输出与有机碳输出有关，但下沉颗粒中溶解 Cr 的深水释放并不直接依赖于有机碳呼吸，正如 Cr、氧气利用和海洋再生之间的不同趋势所表明的。有机相关的常量营养素（例如 N、P）。孔隙水和底水数据表明底栖 Cr 通量在局部很重要，可能在全球范围内也很重要。我们的 CaCO _{3 中}的孔隙水溶解 Cr 通量富位点可能是由下沉颗粒从水柱中清除的 Cr 的重新释放驱动的，而岩性相的贡献很小。我们认为这与迄今为止在最低氧区以下水体中发现的最高公海 [Cr] 一致，这可能反映了深水或表层沉积物中清除的 Cr 的释放。从悬浮颗粒和表层沉积物中释放的铬随着全球${\delta }^{53}$Cr–[Cr] 阵列，支持生物输出和再生在塑造全球 Cr 和 ${\delta }^{53}$Cr 分布。全球中深水 [Cr],${\delta }^{53}$因此，Cr 和 Cr：常量营养素的关系是由循环模式、水团混合、深层 Cr 再生循环和底栖 Cr 源的协同作用形成的。对全球 Cr 分布的生物成因控制表明，沉积 Cr 记录可能反映生物成因以及 O ₂依赖过程，而需要更多的研究来评估基于活跃成岩循环的沉积物 Cr 记录保真度。