Plate tectonics drive deep biosphere microbial community composition [post]

Katherine M. Fullerton, Matthew Schrenk, Mustafa Yucel, Elena Manini, Daniele Fattorini, Marta di Carlo, Francesco Regoli, Mayuko Nakagawa, Francesco Smedile, Costantino Vetriani, Heather Miller, Shaunna Morrison (+5 others)
2019 unpublished
Deep subsurface microbes comprise one of the largest biospheres on Earth, altering the volatiles that move between the deep Earth and the surface. One of the most compelling - yet elusive - questions in geomicrobiology is how large-scale tectonic processes, such as plate subduction at convergent margins, affect the distribution and function of subsurface microorganisms. Here we show that the microbial distribution across a transect of a subducting convergent margin is explained by differences
more » ... ed by differences in subducting parameters between the East Pacific Rise (EPR) in north Costa Rica and the Cocos-Nazca Spreading (CNS) Center in central Costa Rica. The differences in slab dip angle and extensional versus compressional stress regime in the volcanic arc affect microbial distributions through the changes these deep structures exert on fluid geochemistry. In turn, these microbial communities affect the geochemistry and mineralogy of the system by catalyzing iron and sulfur redox reactions and fixing CO 2 into biomass. We conclude that the microbial community structure tracks tectonic processes across this subduction zone and participates in deep volatile cycling and carbon sequestration.
doi:10.31223/osf.io/gyr7n fatcat:75rvhsy54bgnhpac26w3jxh3yy