Carbonate platform production during the Cretaceous
Carbonate platform production during the Cretaceous
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白垩纪碳酸盐台地生产
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
J. Borgomano
中科院分区：
文献类型：
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作者：
A. Pohl;Y. Donnadieu;Y. Goddéris;C. Lanteaume;A. Hairabian;C. Frau;Julien Michel;M. Laugié;J. Reijmer;C. Scotese;J. Borgomano
台地碳酸盐岩是白垩纪沉积物中体积最大的。碳酸盐台地的产量随时间而波动。然而，这些波动的原因尚不清楚，基本机制在很大程度上仍然不受约束。在此基础上，我们记录了白垩纪碳酸盐岩台地保存的长期趋势，并利用气候-碳循环模型探讨了白垩纪碳酸盐岩台地生产的驱动因素。研究表明，浅海碳酸盐保存速率在白垩纪呈单峰模式，在白垩纪中期达到最大值（Albian, 110 Ma）。耦合气候-碳循环模型显示，碳酸盐沉积的这种最大值是由高火山脱气率和广泛的浅海环境的独特组合造成的，浅海环境作为浅海碳酸盐沉积的基质。我们的实验表明，浅海碳酸盐成藏的单峰模式与白垩纪大多数火山脱气情景吻合得很好。研究结果表明，白垩纪浅海碳酸盐生产的一级时间演化反映了大陆构造和火山脱气的变化。通过调节调节空间的地球动力学和优势生物群的翻转可能也起了作用，但在我们的模拟中，解释白垩纪浅海碳酸盐聚集的一级趋势没有必要考虑后者的过程。
Platform carbonates are among the most voluminous of Cretaceous deposits. The production of carbonate platforms fluctuated through time. Yet, the reasons for these fluctuations are not well understood, and the underlying mechanisms remain largely unconstrained. Here we document the long-term trend in Cretaceous carbonate platform preservation based on a new data compilation and use a climate-carbon cycle model to explore the drivers of carbonate platform production during the Cretaceous. We show that neritic carbonate preservation rates followed a unimodal pattern during the Cretaceous and reached maximum values during the mid-Cretaceous (Albian, 110 Ma). Coupled climate-carbon cycle modeling reveals that this maximum in carbonate deposition results from a unique combination of high volcanic degassing rates and widespread shallow-marine environments that served as a substrate for neritic carbonate deposition. Our experiments demonstrate that the unimodal pattern in neritic carbonate accumulation agrees well with most of the volcanic degassing scenarios for the Cretaceous. Our results suggest that the first-order temporal evolution of neritic carbonate production during the Cretaceous reflects changes in continental configuration and volcanic degassing. Geodynamics, by modulating accommodation space, and turnovers in the dominant biota probably played a role as well, but it is not necessary to account for the latter processes to explain the first-order trend in Cretaceous neritic carbonate accumulation in our simulations.