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The research cruise is part of a larger international effort to investigate the origin and nature of microbial communities within basaltic basement below an isolated sediment "pond" located on 7–8 Ma seafloor on the western flank of the Mid-Atlantic Ridge at 23°N. The cornerstone of the program is a transect of borehole “CORKed” microbial observatories being designed to allow long-term (decadal), manipulative, community-based experiments, observations, and sampling. The primary goal of the cruise is the deployment and recovery of seafloor instrument packages on each of the three borehole observatories post drilling and to sample borehole fluids. We also plan to conduct ROV-based sediment sampling and heat flow measurements as well as mapping and rock sampling up the basement outcrops surrounding North Pond. These operations are critical to the success of the larger program aimed at studying the basalt-hosted biosphere. These studies will document and elucidate microbial community composition harbored within a young ridge flank, assess the role of microbes in the weathering of oceanic crust, and quantify relations between crustal hydrogeology and microbial community development. We closely cooperate with colleagues from the US, who have secured complete funding for building all of the borehole and wellhead instruments.

Specifically, we seek to answer the following research questions:
What is the nature of microbial communities harbored in young ridge flanks?
Are these communities unique, particularly in comparison with seafloor and sedimentary communities?
What are the mechanisms for microbial growth within the oceanic crust?
What is the level of microbial activity and abundance within different subsurface areas?
What is the role of microbes in weathering the oceanic crust, under both oxidative and reducing conditions?
How are microbial communities in young basement rocks influenced by subsea-floor hydrogeology?
Does hydrogeology impact the microbial distribution?

Chief scientist:

Prof. Dr. Wolfgang Bach

Research vessel Maria S. Merian

MSM 20/5 Route

Cruise track MSM 20/5

CORK-Observatory (Cowen et al., 2012)

CORK-Observatory (Cowen et al., 2012)