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

洋盆的形成和发展是通过大陆裂谷和海底扩张的构造过程。加州湾（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的沉积物填充物和火山产物的地方之一。然后，可以从回收的沉积物岩心中研究盆地历史。本研究的重点是最近在墨西哥中部GOC的瓜伊马斯盆地钻探和勘探期间回收的~4 km沉积物岩心。这些将被分析和解释，以找出是什么控制了沉积物的成分，沉积物是如何被运输和沉积，以及如何匹配钻井现场之间的沉积层。这项研究有助于在地球科学领域培训妇女和代表性不足的少数民族，支持由两名女教授指导的三名硕士生组成的研究小组。工作成果将通过在圣莫尼卡山国家娱乐区的外联活动向公众宣传。 这个地方是美国最大的城市公园。项目团队将创建新的地质实地考察材料，以帮助游客了解公园地质。 实地考察将包括与瓜伊马斯盆地类似的海洋沉积岩和火山岩露头。对国际海洋发现计划远征385岩心进行岩相和岩相分析，并与先前的深海钻探项目第64航次钻探结果相结合，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。该盆地分析不可或缺的一部分是潜在基准面、火山灰和其他桑迪事件（风暴、地震）床的定义，它们可以定义在整个盆地中随时间推移的沉积物包，以显示沉积物累积速率的模式。 385号考察队新发现的火山灰和火山砂粉砂层将使用各种岩相学和成像技术进行指纹识别，并使用其主要和次要元素地球化学分析以及矿物相的元素组成进一步记录其来源。深盆中的桑迪重力-物质流床将显示出指示其输送机制的相和碎屑模式模式，例如：A）三角洲前缘洪水和物质流失; B）沿大陆坡的地震引起的物质流失沿着;以及C）热带风暴对海岸沉积物的冲刷。这项研究与其他远征385研究相结合，将使瓜伊马斯盆地可以说是世界上研究最好的年轻海洋盆地和新生海洋盆地的早期沉积史的模型。这个奖项反映了NSF的法定使命，并已被认为是值得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的支持。

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.