The secular trend of seawater strontium isotope ratio (⁸⁷Sr/⁸⁶Sr) reflects changes in the relative contributions of continental versus mantle reservoirs to ocean composition, and informs global tectonic events, weathering rates and biogeochemical cycling through Earth history. However, the Precambrian seawater ⁸⁷Sr/⁸⁶Sr curve is known in far less detail than its Phanerozoic counterpart. For this study, we compiled 2249 strontium isotope ratios of Precambrian marine sedimentary rocks published since 2002, alongside previously compiled older data. Here we evaluate the uncertainty of all published data for constraining coeval seawater ⁸⁷Sr/⁸⁶Sr using four criteria (depositional environment, diagenetic alteration, age constraint and dissolution method). The resultant seawater ⁸⁷Sr/⁸⁶Sr curve uses mainly ‘high certainty’ data and shows an overall increasing trend from ~0.7005 at c. 3.5 Ga to ≥0.7089 towards the end of the Ediacaran Period. The improved curve shows an earlier deviation of seawater ⁸⁷Sr/⁸⁶Sr from the contemporaneous mantle by c. 3.5 Ga, which might reflect the first significant emergence of evolved continental crust related to nascent tectonics. Additionally, the updated curve records two major rises at 2.5-2.2 Ga and 1.9-1.7 Ga in addition to a well-established event at 0.8-0.5 Ga. Despite the relative scarcity of high-certainty data, these two increases are consistent with enhanced continental weathering following the onset of oxidative weathering and assembly of the supercontinent Nuna, respectively. Although confirmation of these two events awaits more high-certainty data, Precambrian seawater ⁸⁷Sr/⁸⁶Sr experienced stronger oscillations and better correspondence with supercontinent cycles than previously shown.

海水锶同位素比 ( ⁸⁷ Sr/ ⁸⁶ Sr)的长期趋势反映了大陆与地幔储层对海洋组成的相对贡献的变化，并为地球历史上的全球构造事件、风化率和生物地球化学循环提供信息。然而，前寒武纪海水⁸⁷ Sr/ ⁸⁶ Sr 曲线的细节远不如显生宙的对应曲线那么详细。在这项研究中，我们汇编了 2002 年以来发表的前寒武纪海相沉积岩的 2249 锶同位素比率，以及之前汇编的旧数据。在这里，我们评估了所有已发布数据的不确定性，用于约束同期海水⁸⁷ Sr/ ⁸⁶Sr 使用四个标准（沉积环境、成岩改变、年龄约束和溶解方法）。由此产生的海水⁸⁷ Sr/ ⁸⁶ Sr 曲线主要使用“高确定性”数据，并在 c 处显示从 ~0.7005 开始的总体增加趋势。3.5 Ga 到 ≥ 0.7089 到埃迪卡拉纪末期。改进后的曲线显示了较早的海水⁸⁷ Sr/ ⁸⁶偏差来自同时代地幔的 Sr 由 c。3.5 Ga，这可能反映了与新生构造相关的演化大陆地壳的首次显着出现。此外，更新后的曲线记录了 2.5-2.2 Ga 和 1.9-1.7 Ga 的两次主要上升，以及 0.8-0.5 Ga 的公认事件。尽管高确定性数据相对稀缺，但这两次增加与增强分别发生氧化风化和超级大陆 Nuna 组装后的大陆风化。尽管这两个事件的确认等待更多的高确定性数据，但前寒武纪海水⁸⁷ Sr/ ⁸⁶ Sr 经历了比之前显示的更强的振荡和与超大陆循环更好的对应关系。