Abstract

The first sediment N-isotope data on the Permian–Triassic boundary transition of the Verkhoyansk region are obtained. Together with the other published materials on other regions of eastern Russia allow us to distinguish a number of N-isotope intervals of various ranks in the Permian–Triassic of eastern Russia. In addition to the well-known method of reconstructing the redox conditions of the marine environment from N‑isotope data (in combination with data on elevated concentrations of redox-sensitive trace metals), the possibility of using N-isotope data also to determine the direction of temperature changes in the marine environment is substantiated. It is assumed that N-isotope signals are primarily a reflection of events associated with denitrification and N₂ fixation, the main processes of the global nitrogen biogeochemical cycle (NBC). Deviations in the direction of increasing δ¹⁵N values in the considered sections are associated with an increase in upwelling activity and the supply of cool deep waters enriched in the heavy N isotope to the shelf zone; the opposite deviations are associated with a slowdown or cessation of inflow of cool deep waters. The N-isotope data obtained, in combination with the published materials on O-isotope thermometry in the Tethyan Superrealm during the Permian and Triassic, indicate a very likely coincidence of the direction of temperature changes caused by both regional (upwelling) and global (climatic) events of that time. In this regard, the reconstructions of the marine environment that we conduct by the example of the Permian–Triassic sections of Northeast Asia (Verkhoyansk, Kolyma–Omolon, and South Primorye) seem to be appropriate, although they require additional confirmation on the material from other sections of the world. The problems associated with differences in the average δ¹⁵N values in the Permian–Triassic sections of different provinces of the Boreal Superrealm, as well as other superrealms, are considered.

中文翻译：

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Verkhoyansk地区（东北亚）二叠纪-三叠纪边界层粘土沉积物中氮同位素组成的变化及其对海洋环境重建的意义

摘要

获得了Verkhoyansk地区二叠纪-三叠纪边界过渡的第一个沉积物N同位素数据。结合俄罗斯东部其他地区的其他已出版材料，我们可以区分俄罗斯东部二叠纪-三叠纪的各种等级的N同位素间隔。除了从N同位素数据（结合高浓度的对氧化还原敏感的痕量金属的数据）重建海洋环境氧化还原条件的众所周知的方法之外，还可以使用N同位素数据来确定海洋环境的氧化还原条件。海洋环境中温度变化的方向已得到证实。假设N同位素信号主要是与反硝化和N ₂相关的事件的反映固定，这是全球氮生物地球化学循环（NBC）的主要过程。在δ增加的方向上的偏差¹⁵所考虑的部分中的N值与上升活动的增加以及富含重氮同位素的冷深水向陆架区的供应有关；相反的偏差与凉爽的深水流入速度的减慢或停止有关。所获得的N同位素数据与二叠纪和三叠纪特提斯超界O同位素测温的已发表资料相结合，表明由区域（上升流）和全球（气候）引起的温度变化方向很可能是一致的）当时的事件。在这方面，以东北亚的二叠纪-三叠纪（Verkhoyansk，Kolyma-Omolon和South Primorye）为例，对海洋环境进行重建似乎是适当的，尽管他们需要对世界其他地区的材料进行额外的确认。与平均δ差异有关的问题在北方超领域的不同省以及其他超领域的二叠纪-三叠纪剖面中考虑了¹⁵ N值。