Paper No. 134-11
Presentation Time: 4:30 PM
ORIGIN AND FATE OF METHANE IN THE CENTRAL AMERICAN CONVERGENT MARGIN
SELCI, Matteo1, CASCONE, Martina2, ROGERS, TJ3, VITALE BROVARONE, Alberto4, RAMÍREZ UMAÑA, Carlos José5, BEAUDRY, Patrick6, ONO, Shuhei7, JESSEN, Gerdhard8, SCHRENK, Matt9, DE MOOR, Maarten10, BARRY, Peter11, CORDONE, Angelina12, LLOYD, Karen3 and GIOVANNELLI, Donato13, (1)Marine and Coastal Science, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901; Department of Biology, University of Naples Federico II, Via Vicinale Cupa Cintia, 21, Naples, Naples 80126, Italy, (2)Department of Biology, University of Naples Federico II, Via Vicinale Cupa Cintia, 21, Naples, Naples 80126, Italy, (3)Department of Biology, University of Tennessee, Knoxville, TN 37996, (4)Department of Biological, Geological, and Environmental Sciences, Bologna, Bologna 40126, Italy, (5)Servicio Geológico Ambiental (SEGEOAM) Costa Rica, Heredia, Heredia 3922, Costa Rica, (6)Department of Earth, Atmospheric, and Planetary Sciences, Johns Hopkins University, Cambridge, MA 02139, (7)Massachusetts Institute of Technology, Cambridge, MA 02139, (8)Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Valdivia 0000, Chile, (9)Department of Earth & Environmental Sciences, Michigan State University, East Lansing, MI 48824, (10)OVSICORI, Heredia, Heredia 2386-3000, Costa Rica, (11)Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Boston, MA 02543, (12)Department of Biology, University of Naples Federico II, Naples, Naples 80126, Italy, (13)Department of Biology, University of Naples Federico II, Via Vicinale Cupa Cintia, 21, Naples, Naples 80126, Italy; National Research Council – Institute of Marine Biological Resources and Biotechnologies - CNR-IRBIM, Ancona, Ancona 60125, Italy; Marine and Coastal Science, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901; Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Boston, MA 02543; Earth and Life Science Institute, Tokyo Institute of Technology, Tokyo, Tokyo 152-8550, Japan
Convergent margins are gateways to Earth’s interior where volatile species such as carbon, water, hydrogen, and sulfur are cycled between the surface and the interior of the planet. Here, carbon is recycled from deep reservoirs in two main forms: oxidized carbon as carbon dioxide, and reduced carbon in the form of methane. While the former is quantitatively more important and its volcanic fluxes have been better constrained, the latter can supply needed electrons to microbiological communities and may contribute to greenhouse effects and climate stability. Understanding the geological and biological processes underpinning the origin and fate of methane in convergent margins is thus pivotal to constrain deep carbon cycling and redox balance. Here, we present data from 47 geothermal deeply-sourced seeps spanning the Costa Rican and Panamanian convergent margins. By combining information about the diversity of methane-cycling prokaryotes with clumped methane isotope data, we are able to provide an unprecedented view of the geobiological processes controlling methane cycling in convergent margins. Our data suggest that the hosting rock type and specific geological setting in the convergent margins exert a strong control over the quantity and isotopic signature of the methane cycled to the surface. This suggests that some geological settings promote either methane production, methane oxidation, or biological input. Hence, we propose the geological setting as the main factor in controlling how geological and biological secondary processes overprint the deeper methane signal and affect its fate within convergent margins.
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