Off-axis Sills of Guaymas Basin: Implications for Thermogenic-carbon Flux of a Sedimented Rift Basin

这是一个为期10.5天的巡航项目，目的是在瓜伊马斯盆地的一大片离轴海底收集深拖曳侧扫声纳和啁啾海底剖面数据、CTD测量数据、水样和TowCam图像，以确定喷发流体和气体的区域。这项工作将检验这样一种假设，即在瓜伊马斯盆地，富碳流体和气体的大量喷发是由于离轴岩浆侵入富有机沉积而产生的热生反应的结果。这些数据将识别指示现在和过去喷发的水深和海底特征，如土丘、麻点和断层；图像和照片高后向散射特征，如细菌垫、自生碳酸盐或指示流体流动的生物群落；并通过对水样的分析，提供了一种手段，以区分离轴沉积海脊环境中甲烷和其他碳氢化合物的生物来源和热源。这项工作支持IODP海洋诞生任务提案和IODP 658全面提案，涉及北大西洋解体期间的基床生产和甲烷生成。该项目通过墨西哥国立自治大学的Bill Bandy博士和Carlos Mortera博士的参与促进国际合作，并通过两名美国研究生和两名墨西哥研究生参与研究巡航和随后的分析来促进教育。

This is a project to conduct a 10.5-day cruise to collect deep-towed sidescan sonar and chirp sub-bottom profile data, CTD measurements, water samples, and TowCam imagery over a large region of the off-axis seafloor in Guaymas Basin in order to identify areas of venting fluid and gas. This work will test the hypothesis that substantial venting of carbon-rich fluid and gas occurs off axis in Guaymas Basin as a result of thermogenic reactions driven by off-axis magmatic intrusion into organic-rich sediments.These data will identify bathymetric and sub-bottom features such as mounds, pock marks, and faults that are indicative of present and past venting; image and photograph high backscatter features such as bacterial mats, authigenic carbonate, or biological communities that are indicative of fluid flux; and provide a means, through analysis of water samples, to distinguish between biogenic and thermogenic sources of methane and other hydrocarbons in the off-axis sedimented ridge setting.This work supports IODP Birth of Oceans Mission Proposal and IODP proposal 658 Full related to sill production and methane generation during breakup of N. Atlantic.Broader Impacts This effort will contribute to knowledge of sources and sinks in the global carbon cycle, which is a strong forcing function in past and present climate change. The project promotes international collaboration through the participation of Dr. Bill Bandy and Dr. Carlos Mortera of Universidad Nacional Autónoma de México, and it promotes education through the participation of two U.S. and two Mexican graduate students in the research cruise and subsequent analyses.