The Cretaceous-Paleogene (K-Pg) boundary in the shallow northeastern Mexican foreland basins: Evidence for paleoseismic liquefaction, tsunami deposition, and Chicxulub ejecta

墨西哥东北部前陆盆地浅层白垩纪-古近纪（K-Pg）边界：古地震液化、海啸沉积和希克苏鲁伯喷射物的证据

• 批准号: 87549721
• 负责人: Dr. Peter Schulte
• 金额: --
• 依托单位: Forschungsschwerpunkt Krustendynamik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/87549721?language=en
• 关键词: Cretaceous; Paleogene; Pg; boundary; shallow

Understanding the depositional sequence and composition of impact ejecta is critical to correct interpretation of timing and influence of the Chicxulub impact regarding the mass extinctions at the Cretaceous-Paleogene (K-Pg) boundary. Preliminary investigations suggest that the shallow La Popa and Parras foreland basins in northeastern Mexico both feature outstanding, continuous 3D exposures of a Chicxulub ejecta-rich K-Pg boundary event deposit. Our data shows evidence for possibly seismic-induced sediment liquefaction followed by a series of ejecta-bearing mass-flows that may be interpreted as impact-related tsunamideposits. Moreover, silicic and carbonate ejecta textures are excellently preserved and even relict glass spherules are present. Therefore, this project aims to (i) document the sedimentology, mineralogy, and paleontology of the K-Pg event deposit, (ii) investigate the petrology of the Chicxulub ejecta, and (iii) link the K-Pg boundary sequence in the shallow foreland basins to proximal deep-water K-Pg sites in the Gulf of Mexico and the Atlantic. We intend to improve current ejecta distribution-deposition models, reveal the age of Chicxulub regarding the K-Pg boundary, and constrain ejecta origin and formation processes as well as the release of climatically-sensitive gases during the impact.

了解沉积序列和成分的影响喷出物是至关重要的正确解释的时间和影响的希克苏鲁布的影响，在质量的沉积物在古近系-古近系（K-Pg）边界。初步调查表明，墨西哥东北部的拉波帕和帕拉斯浅前陆盆地都具有希克苏鲁布喷出物富集的K-Pg边界事件存款的突出的、连续的3D暴露。我们的数据显示，可能是地震引起的沉积物液化的证据，随后是一系列的喷出物轴承质量流，可能被解释为影响相关的海啸。此外，火山岩和碳酸盐喷出物结构保存良好，甚至存在残余玻璃球。因此，本项目旨在（i）记录K-Pg事件存款的沉积学、矿物学和古生物学，（ii）调查希克苏鲁布喷出物的岩石学，以及（iii）将浅前陆盆地中的K-Pg边界序列与墨西哥湾和大西洋中的近端深水K-Pg站点联系起来。我们打算改进目前的喷出物分布沉积模型，揭示希克苏鲁布的年龄关于K-Pg边界，并限制喷出物的起源和形成过程，以及释放的气候敏感的气体在影响。