Abstract Carbonaceous calcitic chalk from a 50-m stratigraphic sample interval (n = 35) of the Maastrichtian-Danian Muwaqqar Chalk Marl (MCM) Formation, Jordan, has elevated concentrations of biophile and/or redox-sensitive trace metals (Mo, Ni, V, U, Cr, Cd, Ag, Se, and P) which indicate enhanced paleo-bioproductivity, biodegradation and remineralization under reducing conditions. Very low concentrations in Mn and Ba suggest a relatively open system for components mobile under reducing conditions. The last 800,000 years to the K/Pg boundary are not exposed in Jordan, but the stratigraphic 20-m-interval below and above the hiatus of the K/Pg transition (n = 8) with 2.6 ± 1.8 wt% organic C is particularly metal-enriched with average bulk-rock contents of 132 ppm Mo, 177 ppm Ni, 363 ppm V, 576 ppm Zn, 39 ppm Se, 1.4 ppm Ag, 106 ppm Cd, 474 ppm Cr. These concentrations are dominantly of authigenous origin, when normalized to PAAS, i.e. 100 % Mo, 100% Ag, 100% Cd, 96% Cr, 95% Ni, 95% Zn, 80% V authigenous, and testify to ≥90% of biodegradation of planktonic debris by anaerobic bacterial activity at or near the seafloor. The depositional environment is euxinic, and Mo/TOC ratios from

中文翻译：

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约旦中部白垩纪/古近纪过渡附近碳质白垩的地球化学特征：来自再矿化方解石浮游生物的氧化还原敏感和亲生物元素的强金属富集

摘要 来自约旦 Maastrichtian-Danian Muwaqqar Chalk Marl (MCM) 组 50 米地层采样间隔 (n = 35) 的碳质方解石白垩具有较高浓度的亲生物和/或氧化还原敏感痕量金属（Mo、Ni、 V、U、Cr、Cd、Ag、Se 和 P）表明在还原条件下古生物生产力、生物降解和再矿化增强。Mn 和 Ba 中非常低的浓度表明对于在还原条件下移动的组分来说是一个相对开放的系统。到 K/Pg 边界的最后 800,000 年未在约旦出露，但在 K/Pg 转变中断处（n = 8）下方和上方 20 米间隔的地层中，有机碳含量为 2.6 ± 1.8 wt%富含金属，平均散装岩石含量为 132 ppm Mo、177 ppm Ni、363 ppm V、576 ppm Zn、39 ppm Se、1.4 ppm Ag、106 ppm Cd、474 ppm Cr。这些浓度主要是自产的，当归一化到 PAAS 时，即 100% Mo、100% Ag、100% Cd、96% Cr、95% Ni、95% Zn、80% V 是自产的，并证明≥90%通过海底或海底附近的厌氧细菌活动对浮游生物碎片进行生物降解。沉积环境为富氧环境，Mo/TOC 比值从