Triple oxygen isotope and TOC_TS_Hg_P data for JQ3 core samples during the MOE

The “boring” Mesoproterozoic may not be low-oxygen and less productive as previously thought with several oxygenation events (MOE) and complex eukaryote. However, since oxygenic photosynthesis is the primary source of O₂, poor constraint of oxygenic gross primary productivity (GPP) make it difficult to explain the MOE. Here, we present Δ′¹⁷O values of carbonate-associated sulfates (CAS) and Hg-C-S-P data covering the MOE (ca. 1.57 Ga) to explore the relationship between the GPP and MOE. Unlike the strongly negative Δ′¹⁷O values (down to −0.88‰) reported for the less productive mid-Proterozoic biosphere, our slightly negative Δ′¹⁷O_CAS (−0.1‰) values suggest up to 4 times of the modern GPP during the MOE. Such high GPP may be stimulated by enhanced phosphus input and more complex eukaryote ecosystem. We consider that sufficient GPP, along with efficient organic matter burial, may have drived the MOE and highlighted a short-lived but more productive biosphere in the “boring” Mesoproterozoic.