Immediately before the extinction of the end‐Guadalupian (Middle Permian; ca 260 Ma), a significant change to the global carbon cycle occurred in the superocean Panthalassa, as indicated by a prominent positive δ¹³C excursion called the Kamura event. However, the causes of this event and its connection to the major extinction of marine invertebrates remain unclear. To understand the mutual relationships between these changes, we analyzed the sulfur isotope ratio of the carbonate‐associated sulfate (CAS) and HCl‐insoluble residue, as well as the carbon isotope ratio of bulk organic matter, for the Middle‐Upper Permian carbonates of an accreted mid‐oceanic paleo‐atoll complex from Japan, where the Kamura event was first documented. We detected the following unique aspects of the stable carbon and sulfur isotope records. First, the extremely high δ¹³C values of carbonate (δ¹³C_carb) over +5 ‰ during the Capitanian (late Guadalupian) were associated with large isotopic differences between carbonate and organic matter (Δ¹³C = δ¹³C_carb − δ¹³C_org). We infer that the Capitanian Kamura event reflected an unusually large amount of dissolved organic matter in the expanded oxygen minimum zone at mid‐depth. Second, the δ³⁴S values of CAS (δ³⁴S_CAS) were inversely correlated with the δ¹³C_carb values during the Capitanian to early Wuchiapingian (early Late Permian) interval. The Capitanian trend may have appeared under increased oceanic sulfate conditions, which were accelerated by intense volcanic outgassing. Bacterial sulfate reduction with increased sulfate concentrations in seawater may have stimulated the production of pyrite that may have incorporated iron in pre‐existing iron hydroxide/oxide. This stimulated phosphorus release, which enhanced organic matter production and resulted in high δ¹³C_carb. Low δ³⁴S_CAS values under high sulfate concentrations were maintained and the continuous supply of sulfate cannot by explained only by the volcanic eruption of the Emeishan Trap, which has been proposed as a cause of the extinction. The Wuchiapingian δ³⁴S_CAS–δ¹³C_carb correlation, likely related to low sulfate concentration, may have been caused by the removal of oceanic sulfate through the massive evaporite deposition.

中文翻译：

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Guadalupian-Lopingian（二叠纪）中-Panthalassa的硫和碳同位素系统：日本增生的古钟形碳酸盐中的δ34S和δ13C剖面

（中二叠统;最终瓜的消光之前立即CA 260马），全球碳循环中显著变化发生在SUPEROCEAN泛大洋，由一个突出的正δ所指示¹³C游览称为Kamura事件。但是，该事件的原因及其与海洋无脊椎动物的大灭绝的联系仍不清楚。为了理解这些变化之间的相互关系，我们分析了中上二叠统碳酸盐岩的碳酸盐伴生硫酸盐（CAS）和不溶于HCl的残留物的硫同位素比率，以及大部分有机物的碳同位素比率。日本最早的记载有镰仓事件的日本洋中古太平洋环礁群。我们检测到了稳定的碳和硫同位素记录的以下独特方面。首先，非常高的δ ¹³碳酸盐的C值（δ ¹³ C ^_{碳水化合物}）的匹（晚瓜）期间在5‰用碳酸盐和有机物质（Δ之间的大的同位素差异有关¹³ C =δ ¹³ Ç_{碳水化合物}δ - ¹³ Ç_组织）。我们推断，卡皮塔尼亚镰仓事件反映了中深度扩展的最小氧气带中异常大量的溶解有机物。其次，δ ³⁴ šCAS（δ值³⁴小号_CAS）与δ呈负相关¹³ Ç_{碳水化合物}在Capitanian到Wuchiapingian早期（二叠纪晚期）之间的值。Capitanian趋势可能是在海洋硫酸盐条件增加的情况下出现的，而剧烈的火山放气又加速了这种情况。随着海水中硫酸盐浓度的升高，硫酸盐细菌的减少可能刺激了黄铁矿的产生，该黄铁矿可能将铁掺入了预先存在的氢氧化铁/氧化物中。此受激磷的释放，这增强了有机物质生产，并导致高δ ¹³ Ç_{碳水化合物}。低δ ³⁴小号_CAS在高浓度硫酸盐下仍保持了最高值，而仅通过峨眉山陷阱的火山喷发无法解释硫酸盐的持续供应，这被认为是造成灭绝的原因。的吴家坪δ ³⁴小号_CAS -δ ¹³ Ç_{碳水化合物}的相关性，可能与硫酸浓度低，可能已经由通过大量蒸发盐沉积除去海洋硫酸盐引起的。