...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Silicon isotopes reveal a decline in oceanic dissolved silicon driven by biosilicification: A prerequisite for the Cambrian Explosion?
【24h】

Silicon isotopes reveal a decline in oceanic dissolved silicon driven by biosilicification: A prerequisite for the Cambrian Explosion?

机译：硅同位素揭示了由生物化驱动的海洋溶解硅的下降：寒武纪爆炸的先决条件？

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Early Phanerozoic witnessed one of the most important events in Earth history - the Cambrian Explosion. There is also a consensus that at roughly the same time oceanic dissolved silicon (DSi) concentrations decreased from close to saturation to somewhere below saturation. Yet the timing and magnitude of the putative DSi decrease, and any relationship with biological innovations, remain poorly known. Here, we study the widespread chert formed during the Ediacaran-Cambrian transition (ca. 551-522 Ma) on the Yangtze Block, South China. Major and trace element geochemistry suggest the silicon for the chert is predominantly sourced from seawater, and most likely precipitated via adsorption on organic matter and uptake by silica-secreting organisms. New and compiled silicon isotope data from seven sections spanning the E-C boundary show an increase in divergence of delta Si-30 values at ca. 533 Ma. Using mass-balance arguments, we interpret this as evidence that the radiation of siliceous sponges and radiolarians contributed to a substantial (ca. 80%) decrease in oceanic DSi concentrations, which is corroborated by fossil records and simple box-models. Reduced oceanic DSi may reduce the effort needed to maintain intracellular Si concentrations below the level at which harmful Si precipitation in organismal cytoplasm occurs. This energy can be reallocated to other metabolic pathways of new functional types, potentially the establishment of suspension-feeding communities that triggered Phanerozoic-type mixground ecology. Therefore, the early appearance of silicifiers (similar to 540-530 Ma) may have made conditions more favorable for the main stage (similar to 520 Ma) of Cambrian Explosion in functional and ecological diversification. (C) 2021 Elsevier B.V. All rights reserved.
机译：显生宙早期见证了地球历史上最重要的事件之一——寒武纪爆发。还有一个共识是，大约在同一时间，海洋溶解硅（DSi）浓度从接近饱和降至低于饱和的某个位置。然而，人们对假定的DSi下降的时间和幅度以及与生物创新的任何关系仍然知之甚少。在这里，我们研究了扬子地块埃迪卡拉纪-寒武纪过渡期（约551-522 Ma）形成的广泛硅质岩。常量和微量元素地球化学表明，硅质岩中的硅主要来源于海水，很可能是通过吸附在有机质上并被分泌硅的生物吸收而沉淀的。来自跨越E-C边界的七个剖面的新的和汇编的硅同位素数据显示，δSi-30值在约533 Ma处的散度增加。利用质量平衡论点，我们将其解释为硅质海绵和放射虫的辐射导致海洋DSi浓度大幅下降（约80%）的证据，这一点得到化石记录和简单盒子模型的证实。减少海洋DSi可能会减少将细胞内Si浓度维持在有机体细胞质中有害Si沉淀水平以下所需的努力。这种能量可以重新分配到新功能类型的其他代谢途径，可能是建立悬浮饲养群落，触发显生宙型混合地生态。因此，硅化剂的早期出现（类似于540-530 Ma）可能使寒武纪爆发的主要阶段（类似于520 Ma）在功能和生态多样化方面更加有利。（c）2021爱思唯尔B.V.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号