10:00 AM - 10:15 AM
[SCG67-05] Current Status of Drilling-Related Plans to Study Consequences of Bend-Fault Serpentinization During Plate Bending offshore Nicaragua (Outcome from the June 2016 BFS/H-ODIN Workshop)
Keywords:Bend-Fault Serpentinization, Outer Rise, Hydrothermal System, Scientific Drilling
In-situ sampling of rocks and fluid tracers is a key tool to make further progress in our understanding of BFS, its implications for the hydrothermal system(s?) that can develop during plate bending, the extent of deep life within these systems, and the resulting chemical interactions between the downgoing plate and seawater. Offshore Nicaragua is a prime site for drilling-related study of this process because this is the place where ongoing BFS occurs in the the world’s shallowest environment (2.9-3.4km water depth).
In June 2016 a group of interested scientists met at the IODP workshop “Bend-Fault Serpentinization, drilling proposals using the D/V Chikyu” to assess the best strategy for using scientific drilling to explore BFS at complementary sites at the Middle American Trench offshore Nicaragua and the Japan Trench. The drilling-oriented goals of the workshop were to refine scientific objectives, drill sites, and strategies for scientific drilling in the outer rise region in order to understand the nature of the bend-fault hydration in the incoming plate. We reached a provisional consensus on the best approaches to make the most rapid progress towards better understanding of this frontier area of Earth Science. The workshop discussed deep drilling plans, but it was felt that a staged approach is preferable for effective study of this system. A dual-mode drilling strategy was proposed: (Stage I), D/V JOIDES Resolution or D/V Chikyu drilling through the upper parts of the bend-fault system to better understand the chemistry and shallow fluids, fluid flow, and bend-fault-linked microbial ecosystems, and also assess and improve our current technologies and strategies for drilling through bend-faults, and (Stage II), a MoHole-type drilling strategy to sample an intact crustal and mantle section through 1km below the ~5.5km-deep crust-mantle boundary that has direct relevance to many M2M (MoHole) science objectives. This talk will briefly summarize the known constraints on BFS in this region, and then discuss the proposed strategy for future IODP investigation of this system. Any interested scientists are welcome to join the ‘BFS Science Team’ and help in the preparation of a full IODP proposal for Fall 2017.