The Cambro-Ordovician interval marks a significant transition from extinction to bio-diversification in deep time. However, the relationship of bio-transition to volcanism, commonly characterized by mercury (Hg) systematics in sedimentary records, has not been examined. We present the first Cambro-Ordovician Hg systematics from the Scandinavian Alum Shale. Our results show pronounced Furongian Hg enrichments, coupled with positive Δ¹⁹⁹Hg, Δ²⁰⁰Hg, and Δ²⁰¹Hg values and negative Δ²⁰⁴Hg values that we ascribe to atmospheric Hg transport over long-distances, while Early Ordovician Hg anomalies, characterized by near-zero mass-independent isotope values, indicative of submarine source. Our findings are supported by two new proxies: molybdenum-Hg and vanadium-δ²⁰²Hg co-variations, demonstrating Hg systematics were strongly influenced by changes in source and depositional conditions. Constrained by a synchronous atmospheric-tectonic-oceanic model, we hypothesize Furongian subaerial volcanism contributed to global extinction and oceanic anoxia, whereas Early Ordovician submarine volcanism concurrent with ocean water upwelling promoted the nascent bio-diversification.

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通过富集钼和钒改善汞系统学：来自寒武纪-奥陶纪边界的新见解

寒武纪-奥陶纪标志着深部从灭绝到生物多样性的重大转变。然而，生物转化与火山作用的关系，通常以沉积记录中的汞（Hg）系统学为特征，尚未得到研究。我们首次展示了来自斯堪的纳维亚明矾页岩的寒武纪-奥陶纪汞系统学。我们的结果显示了明显的芙蓉纪汞富集，加上正的 Δ ¹⁹⁹ Hg、Δ ²⁰⁰ Hg 和 Δ ²⁰¹ Hg 值以及负的 Δ ²⁰⁴ Hg 值，我们将其归因于大气汞的长距离输运，而早奥陶世的汞异常，其特征为接近于零的质量无关同位素值，表明来自海底。我们的发现得到了两个新指标的支持：钼-Hg 和钒-δ ²⁰² Hg 共变，表明汞系统学受到来源和沉积条件变化的强烈影响。受同步大气-构造-海洋模型的约束，我们假设芙蓉纪陆上火山活动导致了全球灭绝和海洋缺氧，而早奥陶世海底火山活动与海水上涌同时促进了新生的生物多样性。