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.

洋盆的形成和成长是在大陆裂陷和海底扩张的构造过程中完成的。加利福尼亚湾（GOC）是地球上为数不多的可以通过海底钻探获得年轻海洋盆地沉积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GOC的Guaymas盆地最近的钻探和勘探中回收的~4 km沉积物岩心。将对这些数据进行分析和解释，以找出控制沉积物组成的因素，沉积物是如何运输和沉积的，以及如何在钻孔点之间匹配沉积层。这项研究有助于培训妇女和代表性不足的少数民族从事地球科学，支持由两名女教授指导的三名硕士研究生组成的研究小组。工作成果将通过在圣莫尼卡山国家游乐区的外展活动向公众传播。这里是美国最大的城市公园。项目团队将制作新的地质实地考察材料，帮助游客了解公园地质。实地考察将包括与瓜伊马斯盆地相似的海相沉积岩和火山岩露头。国际海洋发现计划（International Ocean Discovery Program） 385号远征队（Expedition 385）岩心的岩相和岩相分析，以及与先前的深海钻探项目Leg 64钻探结果的整合，是揭示瓜伊马斯盆地沉积物输送和积聚模式和控制的必要步骤。该盆地分析的组成部分是对潜在基准面、火山灰和其他沙质事件（风暴、地震）床的定义，这些基准面可以定义整个盆地在时间上可联系的沉积物包，以显示沉积物积聚速率的模式。385探险队新发现的火山灰和碎屑火山砂粉层将使用各种岩石学和成像技术进行指纹鉴定，并通过对其主要元素和次要元素的地球化学分析以及矿物相的元素组成进一步记录其来源。深盆砂质重力-质量流床将显示出指示其输送机制的相型和碎屑模式，如：A)三角洲前缘洪水和物质消耗；B)沿大陆斜坡的地震诱发的物质损耗；C)热带风暴冲刷海岸沉积物。这项研究与385考察队的其他研究相结合，将使瓜伊马斯盆地成为世界上研究得最好的年轻海洋盆地，并成为新生海洋盆地早期沉积历史的典范。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。