The Marinoan Snowball Earth glaciation (~650–635 Ma) was followed by an increase in atmospheric O₂ level and the diversification of eukaryotes. These dramatic changes have been assumed to have resulted from the rapid recovery of primary productivity during deglaciation, but this hypothesis has not yet been tested. Carbonate carbon isotope (δ¹³C_carb), closely related to organic matter production and burial, has the potential to provide with the most straightforward evidence for the perturbation in marine carbon cycle. However, individual δ¹³C_carb record might be less well-suited to test this hypothesis than a large data compilation. Here, we analyze 1590 globally-distributed carbonate carbon isotope data from the Marinoan cap carbonate. The least square sum analysis of the shallow-water cap carbonate δ¹³C_carb data indicates that the carbon isotopic composition of seawater dissolved inorganic carbon (DIC, δ¹³C_DIC) was −3.01‰ during cap carbonate precipitation. This result sharply contrasts with the assumed synglacial seawater δ¹³C_DIC value of −5‰, which was verified with a binary mixing model. The 2‰ increase in the seawater δ¹³C_DIC can be attributed to intensive organic matter production and burial during the deglaciation in less than 10⁶ years. Massive organic carbon burial in the wake of the Marinoan Snowball Earth glaciation contributed a postglacial increase of atmospheric O₂ level by 3.8% to 13.4% PAL (present atmospheric level) and thus further facilitated diversification of eukaryotes.

Marinoan Snowball Earth 冰川作用（~650-635 Ma）之后是大气中 O ₂水平的增加和真核生物的多样化。这些巨大的变化被认为是冰川消退期间初级生产力迅速恢复的结果，但这一假设尚未得到检验。碳酸盐碳同位素（δ ¹³ C _carb）与有机物的产生和埋藏密切相关，有可能为海洋碳循环的扰动提供最直接的证据。然而，个别 δ ¹³ C_{碳水化合物}与大型数据汇编相比，记录可能不太适合测试这个假设。在这里，我们分析了来自 Marinoan 盖碳酸盐的 1590 个全球分布的碳酸盐碳同位素数据。浅水盖层碳酸盐δ ¹³ C _carb数据的最小二乘和分析表明，盖层碳酸盐沉淀过程中海水溶解无机碳的碳同位素组成(DIC，δ ¹³ C _DIC )为-3.01‰。该结果与假设的同冰期海水 δ ¹³ C _DIC值 -5‰形成鲜明对比，后者已通过二元混合模型进行验证。海水δ ¹³ C _DIC增加2‰可归因于在不到 10 ⁶ 年的冰消期期间密集的有机物生产和掩埋。Marinoan Snowball Earth 冰川作用之后的大量有机碳埋藏导致冰后大气 O ₂水平增加了 3.8% 至 13.4% PAL（当前大气水平），从而进一步促进了真核生物的多样化。