Carbon and other volatiles in the form of gases, fluids or mineral phases are transported from Earth’s surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth’s deep mantle and shallow crustal reservoirs, as well as Earth’s oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2 × 108 and 1.3 × 1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth’s deep mantle than previously estimated.
This is a preview of subscription content
Subscription info for Chinese customers
We have a dedicated website for our Chinese customers. Please go to naturechina.com to subscribe to this journal.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The freely distributed software PhreeqC (United States Geological Survey) was used to calculate geochemical solubilities, and is available for download at https://www.usgs.gov/software/phreeqc-version-3.
Kelemen, P. B. & Manning, C. E. Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up. Proc. Natl Acad. Sci. USA 112, E3997–E4006 (2015).
Shaw, A. M., Hilton, D. R., Fischer, T. P., Walker, J. A. & Alvarado, G. E. Contrasting He–C relationships in Nicaragua and Costa Rica: insights into C cycling through subduction zones. Earth Planet. Sci. Lett. 214, 499–513 (2003).
Füri, E. et al. Carbon release from submarine seeps at the Costa Rica fore arc: implications for the volatile cycle at the Central America convergent margin. Geochem. Geophys. Geosyst. 11, Q04S21 (2010).
Schwarzenbach, E. M., Früh-Green, G. L., Bernasconi, S. M., Alt, J. C. & Plas, A. Serpentinization and carbon sequestration: a study of two ancient peridotite-hosted hydrothermal systems. Chem. Geol. 351, 115–133 (2013).
McCollom, T. M. & Seewald, J. S. Serpentinites, hydrogen, and life. Elements 9, 129–134 (2013).
Hilton, D. R., Fischer, T. P. & Marty, B. Noble gases and volatile recycling at subduction zones. Rev. Mineral. Geochem. 47, 319–370 (2002).
de Leeuw, G. A. M., Hilton, D. R., Fischer, T. P. & Walker, J. A. The He–CO2 isotope and relative abundance characteristics of geothermal fluids in El Salvador and Honduras: new constraints on volatile mass balance of the Central American Volcanic Arc. Earth Planet. Sci. Lett. 258, 132–146 (2007).
de Moor, J. M. et al. A new sulfur and carbon degassing inventory for the Southern Central American Volcanic Arc: the importance of accurate time-series data sets and possible tectonic processes responsible for temporal variations in arc-scale volatile emissions. Geochem. Geophys. Geosyst. 18, 4437–4468 (2017).
Fryer, P., Ambos, E. L. & Hussong, D. M. Origin and emplacement of Mariana forearc seamounts. Geology 13, 774–777 (1985).
Brown, K. M. The nature and hydrogeologic significance of mud diapirs and diatremes for accretionary systems. J. Geophys. Res. Solid Earth 95, 8969–8982 (1990).
Naif, S., Key, K., Constable, S. & Evans, R. L. Water-rich bending faults at the Middle America Trench. Geochem. Geophys. Geosyst. 16, 2582–2597 (2015).
Gorman, P. J., Kerrick, D. M. & Connolly, J. A. D. Modeling open system metamorphic decarbonation of subducting slabs. Geochem. Geophys. Geosyst. 7, Q04007 (2006).
Vaca, L., Alvarado, A. & Corrales, R. Calcite deposition at Miravalles geothermal field Costa Rica. Geothermics 18, 305–312 (1989).
Corrigan, J., Mann, P. & Ingle, J. C. Jr. Forearc response to subduction of the Cocos ridge, Panama–Costa Rica. Geol. Soc. Am. Bull. 102, 628–652 (1990).
Pacton, M. et al. Viruses as new agents of organomineralization in the geological record. Nat. Commun. 5, 4298 (2014).
Zhu, T. & Dittrich, M. Carbonate precipitation through microbial activities in natural environment, and their potential in biotechnology: a review. Front. Bioeng. Biotechnol. 4, https://doi.org/10.3389/fbioe.2016.00004 (2016).
Berg, I. A. Ecological aspects of the distribution of different autotrophic CO2 fixation pathways. Appl. Environ. Microbiol. 77, 1925–1936 (2011).
Colwell, F. S. & D’Hondt, S. Nature and extent of the deep biosphere. Rev. Mineral. Geochem. 75, 547–574 (2013).
Emerson, J. B., Thomas, B. C., Alvarez, W. & Banfield, J. F. Metagenomic analysis of a high carbon dioxide subsurface microbial community populated by chemolithoautotrophs and bacteria and archaea from candidate phyla. Environ. Microbiol. 18, 1686–1703 (2016).
Harris, R. N. & Wang, K. Thermal models of the middle America trench at the Nicoya Peninsula, Costa Rica. Geophys. Res. Lett. 29, 2010 (2002).
Whiticar, M. J. Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane. Chem. Geol. 161, 291–314 (1999).
McCollom, T. M. & Seewald, J. S. Abiotic synthesis of organic compounds in deep-sea hydrothermal environments. Chem. Rev. 107, 382–401 (2007).
Ozima, M. & Podosek, F. A. Noble Gas Geochemistry (Cambridge Univ. Press, 2002).
Hilton, D. R. The helium and carbon isotope systematics of a continental geothermal system: results from monitoring studies at Long Valley caldera (California, U.S.A.). Chem. Geol. 127, 269–295 (1996).
Mook, W. G., Bommerson, J. C. & Stavermann, W. H. Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide. Earth Planet. Sci. Lett. 22, 169–176 (1974).
Vogel, J. C., Grootes, P. M. & Mook, W. G. Isotopic fractionation between gaseous and dissolved carbon dioxide. Z. Phys. A 230, 225–238 (1970).
Barry, P. H. et al. Helium and carbon isotope systematics of cold “mazuku” CO2 vents and hydrothermal gases and fluids from Rungwe Volcanic Province, southern Tanzania. Chem. Geol. 339, 141–156 (2013).
Audet, P. & Schwartz, S. Y. Hydrologic control of forearc strength and seismicity in the Costa Rican subduction zone. Nat. Geosci. 6, 852–855 (2013).
Wheat, C. G. & Fisher, A. T. Massive, low-temperature hydrothermal flow from a basaltic outcrop on 23 Ma seafloor of the Cocos Plate: chemical constraints and implications. Geochem. Geophys. Geosyst. 9, Q12O14 (2008).
Aiuppa, A. et al. Gas measurements from the Costa Rica–Nicaragua volcanic segment suggest possible along-arc variations in volcanic gas chemistry. Earth Planet. Sci. Lett. 407, 134–147 (2014).
Alt, J. C. et al. Subsurface structure of a submarine hydrothermal system in ocean crust formed at the East Pacific Rise, ODP/IODP Site 1256. Geochem. Geophys. Geosyst. 11, Q10010 (2010).
Carr, M. J., Feigenson, M. D. & Bennett, E. A. Incompatible element and isotopic evidence for tectonic control of source mixing and melt extraction along the Central American arc. Contrib. Mineral. Petrol. 105, 369–380 (1990).
Leeman, W. P., Carr, M. J. & Morris, J. D. Boron geochemistry of the Central American volcanic arc: constraints on the genesis of subduction-related magmas. Geochim. Cosmochim. Acta 58, 149–168 (1994).
Zimmer, M. M. et al. Nitrogen systematics and gas fluxes of subduction zones: insights from Costa Rica arc volatiles. Geochem. Geophys. Geosyst. 5, Q05J11 (2004).
Hilton, D. R. et al. Monitoring of temporal and spatial variations in fumarole helium and carbon dioxide characteristics at Poás and Turrialba volcanoes, Costa Rica (2001–2009). Geochem. J. 44, 431–440 (2010).
Lee, H. et al. Nitrogen recycling at the Costa Rican subduction zone: the role of incoming plate structure. Sci. Rep. 7, 13933 (2017).
House, C. H., Schopf, J. W. & Stetter, K. O. Carbon isotopic fractionation by Archaeans and other thermophilic prokaryotes. Org. Geochem. 34, 345–356 (2003).
Alvarado, G. E. & Vargas, A. G. History of discovery and exploitation of thermal water in Costa Rica. Rev. Geol. Am. Cent. 57, 55–84 (2017).
Marty, B. & Dauphas, N. The nitrogen record of crust–mantle interaction and mantle convection from Archean to present. Earth Planet. Sci. Lett. 206, 397–410 (2003).
Hirschmann, M. M. & Dasgupta, R. The H/C ratios of Earth’s near-surface and deep reservoirs, and consequences for deep Earth volatile cycles. Chem. Geol. 262, 4–16 (2009).
Jelen, B. I., Giovannelli, D. & Falkowski, P. G. The role of microbial electron transfer in the coevolution of the biosphere and geosphere. Annu. Rev. Microbiol. 70, 45–62 (2016).
Li, Z. H., Xu, Z. Q. & Gerya, T. V. Flat versus steep subduction: contrasting modes for the formation and exhumation of high- to ultrahigh-pressure rocks in continental collision zones. Earth Planet. Sci. Lett. 301, 65–77 (2011).
Smithies, R. H., Champion, D. C. & Cassidy, K. F. Formation of Earth’s early Archean continental crust. Precambr. Res. 127, 89–101 (2003).
Abbott, D., Drury, R. & Smith, W. H. F. Flat to steep transition in subduction style. Geology 22, 937–940 (1994).
Holland, H. D. Volcanic gases, black smokers, and the great oxidation event. Geochim. Cosmochim. Acta 66, 3811–3826 (2002).
Kump, L. R., Kasting, J. F. & Barley, M. E. Rise of atmospheric oxygen and the “upside-down” Archean mantle. Geochem. Geophys. Geosyst. 2, 2000GC000114 (2001).
Och, L. M. & Shields-Zhou, G. A. The Neoproterozoic oxygenation event: environmental perturbations and biogeochemical cycling. Earth Sci. Rev. 110, 26–57 (2012).
Bird, P. An updated digital model of plate boundaries. Geochem. Geophys. Geosyst. 4, 1027 (2003).
Protti, M., Gündel, F. & McNally, K. The geometry of the Wadati–Benioff zone under southern Central America and its tectonic significance: results from a high-resolution local seismographic network. Phys. Earth Planet. Inter. 84, 271–287 (1994).
Ryan, W. B. F. et al. Global multi-resolution topography synthesis. Geochem. Geophys. Geosyst. 10, Q03014 (2009).
Giggenbach, W. F. & Goguel, R. L. Methods for the Collection and Analysis of Geothermal and Volcanic Water and Gas Samples. Report CD 2387 53 (Department of Scientific and Industrial Research (Chemistry Division), 1989).
Trull, T. Influx and age constraints on the recycled cosmic dust explanation for high 3He/4He ratios at hotspot volcanos. Noble Gas Geochem. Cosmochem. 77–88 (1994).
Kulongoski, J. T. & Hilton, D. R. A quadrupole-based mass spectrometric system for the determination of noble gas abundances in fluids. Geochem. Geophys. Geosyst. 3, 1–10 (2002).
Barry, P. H. et al. Noble gases solubility models of hydrocarbon charge mechanism in the Sleipner Vest gas field. Geochim. Cosmochim. Acta 194, 291–309 (2016).
Braun, S. et al. Cellular content of biomolecules in sub-seafloor microbial communities. Geochim. Cosmochim. Acta 188, 330–351 (2016).
Giovannelli, D. et al. Diversity and distribution of prokaryotes within a shallow-water pockmark field. Front. Microbiol. https://doi.org/10.3389/fmicb.2016.00941 (2016).
McMahon, S. & Parnell, J. Weighing the deep continental biosphere. FEMS Microbiol. Ecol. 87, 113–120 (2014).
Sano, Y. & Marty, B. Origin of carbon in fumarolic gas from island arcs. Chem. Geol. 119, 265–274 (1995).
Snyder, G., Poreda, R., Hunt, A. & Fehn, U. Regional variations in volatile composition: isotopic evidence for carbonate recycling in the Central American volcanic arc. Geochem. Geophys. Geosyst. 2, 1057 (2001).
Snyder, G., Poreda, R., Fehn, U., & Hunt, A. The geothermal fields of Central America: influence of the subduction process on its volatile composition. Geol. Mag. Central Am. 30, 137–148 (2004).
Wehrmann, H., Hoernle, K., Portnyagin, M., Wiedenbeck, M. & Heydolph, K. Volcanic CO2 output at the Central American subduction zone inferred from melt inclusions in olivine crystals from mafic tephras. Geochem. Geophys. Geosyst. 12, Q06003 (2011).
de Moor, J. M. et al. Turmoil at Turrialba Volcano (Costa Rica): degassing and eruptive processes inferred from high-frequency gas monitoring. J. Geophys. Res. Solid Earth 121, 5761–5775 (2016).
Dawson, P., Chouet, B. & Pitt, A. Tomographic image of a seismically active volcano: Mammoth Mountain, California. J. Geophys. Res. Solid Earth 121, 114–133 (2016).
Mason, E., Edmonds, M. & Turchyn, A. V. Remobilization of crustal carbon may dominate volcanic arc emissions. Science 357, 290–294 (2017).
Chiodini, G., Pappalardo, L., Aiuppa, A. & Caliro, S. The geological CO2 degassing history of a long-lived caldera. Geology 43, 767–770 (2015).
Berrangé, J. P. & Thorpe, R. S. The geology, geochemistry and emplacement of the Cretaceous—Tertiary ophiolitic Nicoya Complex of the Osa Peninsula, southern Costa Rica. Tectonophysics 147, 193–220 (1988).
Giggenbach, W. F. Relative importance of thermodynamic and kinetic processes in governing the chemical and isotopic composition of carbon gases in high-heatflow sedimentary basins. Geochim. Cosmochim. Acta 61, 3763–3785 (1997).
Kuijpers, E. P. The geologic history of the Nicoya Ophiolite Complex, Costa Rica, and its geotectonic significance. Tectonophysics 68, 233–255 (1980).
Schwarzenbach, E. M. et al. Sources and cycling of carbon in continental, serpentinite-hosted alkaline springs in the Voltri Massif, Italy. Lithos 177, 226–244 (2013).
Torgersen, T. Terrestrial helium degassing fluxes and the atmospheric helium budget: implications with respect to the degassing processes of continental crust. Chem. Geol. Isotope Geosci. Sect. 79, 1–14 (1989).
Walther, C. H. E., Flueh, E. R., Ranero, C. R., Von Huene, R. & Strauch, W. Crustal structure across the Pacific margin of Nicaragua: evidence for ophiolitic basement and a shallow mantle sliver. Geophys. J. Int. 141, 759–777 (2000).
Gazel, E., Denyer, P., & Baumgartner, P. O. Magmatic and geotectonic significance of Santa Elena peninsula, Costa Rica. Geol. Acta 4, 0193-202 (2006).
Gazel, E. et al. Plume–subduction interaction in southern Central America: mantle upwelling and slab melting. Lithos 121, 117–134 (2011).
Gazel, E. et al. Continental crust generated in oceanic arcs. Nat. Geosci. 8, 321 (2015).
Madrigal, P. et al. A melt-focusing zone in the lithospheric mantle preserved in the Santa Elena ophiolite, Costa Rica. Lithos 230, 189–205 (2015).
Madrigal, P., Gazel, E., Flores, K. E., Bizimis, M. & Jicha, B. Record of massive upwellings from the Pacific large low shear velocity province. Nat. Commun. 7, 13309 (2016).
Li, L. & Bebout, G. E. Carbon and nitrogen geochemistry of sediments in the Central American convergent margin: Insights regarding subduction input fluxes, diagenesis, and paleoproductivity. J. Geophys. Res. Solid Earth 110, B11202 (2005).
Holloway, J. R. & Blank, J. G. Application of experimental results to COH species in natural melts. Rev. Mineral. 30, 187–230 (1994).
Ohmoto, H. & Rye, R. O. in Geochemistry of Hydrothermal Ore Deposits (ed. Barnes, H. L.) 509–567 (1979).
de Moor, J. M. et al. Short-period volcanic gas precursors to phreatic eruptions: insights from Poás Volcano, Costa Rica. Earth Planet. Sci. Lett. 442, 218–227 (2016).
Kimura, G. et al. (eds) in Proceedings of the Ocean Drilling Program, Initial Reports Vol. 170 Initial Reports, Costa Rica Accretionary Wedge (ODP, 1997).
Barckhausen, U., Ranero, C. R., Huene, R. V., Cande, S. C. & Roeser, H. A. Revised tectonic boundaries in the Cocos Plate off Costa Rica: implications for the segmentation of the convergent margin and for plate tectonic models. J. Geophys. Res. Solid Earth 106, 19207–19220 (2001).
DeMets, C. A new estimate for present day Cocos Caribbean plate motion: Implications for slip along the Central American volcanic arc. Geophys. Res. Lett. 28, 4043–4046 (2001).
Patino, L. C., Carr, M. J. & Feigenson, M. D. Local and regional variations in Central American arc lavas controlled by variations in subducted sediment input. Contrib. Mineral. Petrol. 138, 265–283 (2000).
Von Huene, R., Langseth, M., Nasu, N. & Okada, H. A summary of Cenozoic tectonic history along the IPOD Japan Trench transect. Geol. Soc. Am. Bull. 93, 829–846 (1982).
Parkes, R. J., Cragg, B. A., Fry, J. C., Herbert, R. A. & Wimpenny, J. W. T. Bacterial biomass and activity in deep sediment layers from the Peru margin. Phil. Trans. R. Soc. Lond. A 331, 139–153 (1990).
Biddle, J. F. et al. Heterotrophic Archaea dominate sedimentary subsurface ecosystems off Peru. Proc. Natl Acad. Sci. USA 103, 3846–3851 (2006).
Vannucchi, P. & Tobin, H. Deformation structures and implications for fluid flow at the Costa Rica convergent margin, ODP Sites 1040 and 1043, Leg 170. J. Struct. Geol. 22, 1087–1103 (2000).
Spinelli, G. A. & Underwood, M. B. Character of sediments entering the Costa Rica subduction zone: implications for partitioning of water along the plate interface. Island Arc 13, 432–451 (2004).
Ranero, C. R. et al. Hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis. Geochem. Geophys. Geosyst. 9, Q03S04 (2008).
Spinelli, G. A. & Saffer, D. M. Along-strike variations in underthrust sediment dewatering on the Nicoya margin, Costa Rica related to the updip limit of seismicity. Geophys. Res. Lett. 31, L04613 (2004).
Lloyd, K. G. et al. Effects of dissolved sulfide, pH, and temperature on growth and survival of marine hyperthermophilic archaea. Appl. Environ. Microbiol. 71, 6383–6387 (2005).
Edgcomb, V. P. et al. Survival and growth of two heterotrophic hydrothermal vent archaea, Pyrococcus strain GB-D and Thermococcus fumicolans, under low pH and high sulfide concentrations in combination with high temperature and pressure regimes. Extremophiles 11, 329–342 (2007).
Marlow, J. J. et al. Carbonate-hosted methanotrophy represents an unrecognized methane sink in the deep sea. Nat. Commun. 5, 5094 (2014).
Boetius, A. & Wenzhöfer, F. Seafloor oxygen consumption fuelled by methane from cold seeps. Nat. Geosci. 6, 725 (2013).
Hensen, C., Wallmann, K., Schmidt, M., Ranero, C. R. & Suess, E. Fluid expulsion related to mud extrusion off Costa Rica—a window to the subducting slab. Geology 32, 201–204 (2004).
Colwell, F. S. et al. Estimates of biogenic methane production rates in deep marine sediments at Hydrate Ridge, Cascadia Margin. Appl. Environ. Microbiol. 74, 3444–3452 (2008).
Sánchez-Murillo, R. et al. Geochemical evidence for active tropical serpentinization in the Santa Elena Ophiolite, Costa Rica: an analog of a humid early Earth? Geochem. Geophys. Geosyst. 15, 1783–1800 (2014).
Crespo-Medina, M. et al. Insights into environmental controls on microbial communities in a continental serpentinite aquifer using a microcosm-based approach. Front. Microbiol. 5, 604 (2014).
This work was principally supported by grant G-2016-7206 from the Alfred P. Sloan Foundation and the Deep Carbon Observatory to P.H.B., K.G.L., D.G., K.P., T.L., J.M.d.M. and D. R. Hummer. In addition, P.H.B. was supported by NSF grant 1144559 during a portion of this project. D.G. was supported by an NSF grant (MCB 15–17567), a Deep Life Modelling and Visualization Fellowship from the Deep Carbon Observatory and an ELSI Origins Network (EON) Research Fellowship, which is supported by a grant from the John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. This work was further supported in part by JSPS KAKENHI grants JP17K14412, JP17H06105 and JP17H02989 (awarded to M.N.), an NSF grant OCE-1431598 and a NASA Exobiology grant NNX16AL59G (awarded to K.G.L.), NSF grants 0206113, 0711533 and 1049713 (awarded to T.P.F.), and NSF grants 0003628 and 1049748 (awarded to D. R. Hilton). M.Y. was supported by DEKOSIM grant BAP-08-11-DPT.2012K120880, financed by the Ministry of Development of Turkey. J.M.d.M. acknowledges funding from Universidad Nacional Costa Rica, the World Bank, and the Costa Rican Ley Transitorio 8933 used to acquire a laser carbon isotope system in collaboration with R. Sánchez-Murillo and G. Esquivel-Hernandez. M.N. produced the most data. We thank P. Barcala Dominguez for assistance with figure illustration. We thank B. Deck, M. Wahlen and K. Blackmon for analytical assistance at Scripps Institution of Oceanography. We thank B. Marty, G. Alvarado, M. Broadley, D. Byrne, D. Bekaert, J. Labidi and J. Wade for discussions about the project.
Nature thanks Lorraine Ruzie and the other anonymous reviewer(s) for their contribution to the peer review of this work.
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data figures and tables
Extended Data Fig. 1 CO2/3He versus δ13C for all samples collected, together with mixing lines between mantle (M), organic sediment (S) and carbonate (C) endmembers.
We argue that such mixing relationships cannot easily explain the water data, and that instead carbon isotope fractionation associated with calcite precipitation and chemolithoautotrophy introduces the observed δ13C variations.
Values for northern Costa Rica (a and b) are shown with blue symbols and central Costa Rica (c and d), with yellow symbols. Strong correlations allow prediction of DC concentrations and δ13C values for the sites for which DIC compositions are lacking. The slope of the concentration plots (y) is used to calculate the fraction of DIC and DOC in the sample suites.
Supplementary Table – Sample collection information, as well as helium and carbon isotope data. X-values represent air-normalized 4He/20Ne values (considering solubility in water for fluid samples23), which are used to determine air-corrected 3He/4He values (RC/RA) of the samples24. CO2/3He is calculated using raw He-isotope values (R/RA).
Supplementary Table – Sample location information, cell counts and polycyclic aromatic hydrocarbon (PAH) data.
Supplementary Table – Flux calculations used in the text and to make Figure 4.
Supplementary Table – Water chemistry data, PhreeqC calculations and saturation index (SI) values.
About this article
Cite this article
Barry, P.H., de Moor, J.M., Giovannelli, D. et al. Forearc carbon sink reduces long-term volatile recycling into the mantle. Nature 568, 487–492 (2019). https://doi.org/10.1038/s41586-019-1131-5