The early Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) was characterized by marine deoxygenation and the burial of organic-rich sediments at numerous localities worldwide. However, the extent of marine anoxia and its impact on the sulfur cycle during the T-OAE is currently poorly understood. Here, stable sulfur isotopes of reduced metal-bound sulfur (δ³⁴S_pyrite) and pyrite sulfur concentrations (S_PY) have been analyzed across the Pliensbachian-Toarcian boundary (Pl-To) and the T-OAE from the Sakahogi and Sakuraguchi-dani sections (Japan), which were deposited in the deep and shallow Panthalassic Ocean, respectively. Our data reveal marked positive δ³⁴S_pyrite excursions of >10‰ across both the Pl-To and the T-OAE at Sakahogi, coincident with increases in S_PY, and a positive excursion of >20‰ at the onset of the T-OAE at Sakuraguchi-dani. Whilst the development of deep-water anoxic/euxinic conditions could have resulted in an enhanced burial of pyrite, and also partly contributed to the positive excursion of δ³⁴S_pyrite, variations in δ³⁴S_pyrite at Sakahogi were most likely controlled by elevated export production and/or preservation. On the shallow shelf generally low and highly variable S_PY and the positive shift in δ³⁴S_pyrite were likely attributable mainly to elevated sedimentation rates, with redox playing only a minor role in controlling pyrite abundance. Our discovery of a positive δ³⁴S_pyrite excursion across the Pl-To at Sakahogi indicates a hitherto unrecognized perturbation to the deep-water sulfur cycle, potentially associated with increased seafloor organic matter flux and pyrite burial at this time, consistent with a transient interval of anoxia.

早期Toarcian海洋缺氧事件（T-OAE，~183 Ma）的特点是海洋脱氧和全球许多地方富含有机物沉积物的埋藏。然而，目前人们对 T-OAE 期间海洋缺氧的程度及其对硫循环的影响知之甚少。在这里，已在 Pliensbachian-Toarcian 边界 (Pl-To) 和 Sakahogi 和 Sakuraguchi 的 T-OAE 分析了还原金属结合硫 (δ ³⁴ S_黄铁矿) 和黄铁矿硫浓度 (S _PY ) 的稳定硫同位素- dani 剖面（日本），分别沉积在深海和浅海泛古海洋中。我们的数据揭示了显着的正 δ ³⁴ S_黄铁矿Sakahogi 的 Pl-To 和 T-OAE 的偏移 > 10‰，与 S _PY的增加一致，并且在 Sakuraguchi-dani 的 T-OAE 开始时正偏移 > 20‰。虽然深水缺氧/常温条件的发展可能导致黄铁矿埋藏增加，并且也部分促成了 δ 34 S 黄铁矿的正偏移，但 Sakahogi 的^{δ 34} S^黄铁矿_的变化很可能受到出口增加的控制生产和/或保存。在浅陆架上，S _{PY通常较低且变化较大，δ} ³⁴ S_黄铁矿呈正移可能主要归因于沉降速率升高，氧化还原在控制黄铁矿丰度方面仅起次要作用。我们在 Sakahogi 的 Pl-To 上发现了正 δ ³⁴ S_黄铁矿偏移，这表明对深水硫循环的扰动迄今未被发现，这可能与此时海底有机物质通量和黄铁矿埋藏增加有关，与瞬态间隔一致的缺氧。