Guaymas Basin Stratigraphy, Event Bed Origins, and Correlation: Maximizing Results from the 4 km of Core Recovered on IODP Expedition 385

瓜伊马斯盆地地层学、事件床起源和相关性：最大化 IODP 385 探险队回收的 4 公里岩心的结果

• 批准号: 2133396
• 负责人: Kathleen Marsaglia
• 金额: $ 26.87万
• 依托单位: The University Corporation, Northridge
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2133396&HistoricalAwards=false
• 关键词: Guaymas; Basin; Stratigraphy; Event; Bed

Ocean basins form and grow through the tectonic processes of continental rifting followed by seafloor spreading. The Gulf of California (GOC) is one of few places on earth where the sediment fill and volcanic products of a young ocean basin can be obtained through seafloor drilling. Then, the basin history can be studied from recovered sediment cores. The focus of this study is ~4 km of sediment cores recovered during recent drilling and exploration of the Guaymas Basin, Central GOC, Mexico. These will be analyzed and interpreted to find out what controlled the sediment composition, how the sediment was transported and deposited, and how to match the sedimentary layers among drill sites. This study helps to train women and underrepresented minorities in geoscience, supporting a research team of three master’s degree students mentored by two female professors. The work results will be communicated to the public through outreach activities in the Santa Monica Mountains National Recreation Area. This location is the largest urban park in the United States. The project team will create new geologic field-trip materials to help visitors learn about park geology. The field-trip stops will include outcrops with marine sedimentary and volcanic rocks similar to those found in the Guaymas Basin. Lithofacies and petrofacies analyses of International Ocean Discovery Program Expedition 385 cores and integration with prior Deep Sea Drilling Project Leg 64 drilling results are necessary steps for unraveling the patterns and controls of sediment delivery and accumulation in the Guaymas Basin. Integral to this basin analysis is the definition of potential datums, volcanic ashes and other sandy event (storm, seismic) beds, that can define packages of sediment that are linkable in time across the basin, to show patterns in sediment accumulation rates. Ash and epiclastic volcanic sand-silt beds newly discovered on Expedition 385 will be fingerprinted using a variety of petrographic and imaging techniques, and their provenance further documented using analyses of their major and minor element geochemistry, and elemental composition of mineral phases. Sandy gravity-mass flow beds in the deep basin will show facies and detrital mode patterns indicative of their delivery mechanisms, for example: A) delta-front flood and mass-wasting; B) seismic-induced mass wasting along the continental slope; and C) tropical storm flushing of coastal sediment. This study, in combination with other Expedition 385 research, will make the Guaymas Basin arguably the best studied young ocean basin in the world and a model for the early sedimentary history of nascent ocean basins.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海洋盆地是通过大陆裂谷和海底扩张的构造过程形成和生长的，加利福尼亚湾 (GOC) 是地球上少数几个可以通过海底钻探​​获得年轻海洋盆地沉积物填充物和火山产物的地方之一。然后，可以通过回收的沉积物岩心来研究盆地历史，本研究的重点是在墨西哥中部瓜伊马斯盆地最近的钻探和勘探过程中回收的约 4 公里的沉积物岩心，这些沉积物岩心将被分析和解释。找出控制沉积物成分的因素，沉积物如何运输和沉积，以及如何匹配钻探地点之间的沉积层。这项研究有助于对地球科学领域的女性和代表性不足的少数群体进行培训，为由三名硕士生指导的研究团队提供支持。两名女教授。项目团队将通过在美国最大的城市公园圣莫尼卡山国家休闲区的外展活动向公众传达工作成果。参观者了解实地考察站点将包括与瓜伊马斯盆地中发现的类似的海洋沉积岩和火山岩露头，以及对国际海洋发现计划第 385 次勘探岩心的岩相分析，并与之前的深海钻探项目第 64 段钻探结果相结合。是阐明瓜伊马斯盆地沉积物输送和积累的模式和控制的必要步骤，该盆地分析的组成部分是潜在基准的定义，火山灰和其他沙质事件（风暴、地震）床，可以定义在整个盆地中随时间关联的沉积物包，以显示 385 号探险队新发现的火山灰和碎屑火山砂-粉砂床的沉积物堆积速率模式。使用各种岩相学和成像技术进行指纹识别，并通过对其主要和次要元素地球化学以及砂质重力质量流床的元素组成进行分析来进一步记录其来源。盆地深处的岩相和碎屑模式模式表明其传递机制，例如：A）三角洲前缘洪水和物质流失；B）沿大陆坡地震引起的物质流失；C）热带风暴冲刷；这项研究与 385 号探险队的其他研究相结合，将使瓜伊马斯盆地成为世界上研究最深入的年轻海洋盆地，并成为新生海洋盆地早期沉积历史的模型。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。