Biology Meets Subduction

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Biology Meets Subduction

Integrating deep carbon science in the field

On 11 February 2017, 25 researchers from six nations met in San Jose, Costa Rica for a 12-day sampling expedition across the Costa Rica volcanic arc. Members of the four Deep Carbon Observatory Science Communities are conducting a scientific investigation at Costa Rican volcanic sites through the lenses of biology, chemistry, physics, and geology. This multidisciplinary view is affording researchers from different fields the unique opportunity to work side by side, sharing their insights, and asking questions to achieve a broader picture of the role of carbon in this active volcanic arc.
The sampling expedition “Biology Meets Subduction: A Collaborative and Multidisciplinary Deep Carbon Field Initiative” is designed to develop novel connections between microbiology, volcanic systems, and the cycling of living and dead (biotic and abiotic) carbon as Earth’s plates move and subduct past each other. The goal is to determine how carbon is involved in each of these processes. The knowledge gained will shed light on carbon movement between Earth’s surface and interior and the biological and chemical changes that occur en route. This is a unique opportunity for scientists to share perspectives and knowledge, bringing to bear exciting and novel scientific outcomes.
Why Costa Rica?
The team selected Costa Rica as a study site because several other teams have investigated its active volcanoes and subduction zones, providing important contextual data for further exploration. Offshore, the area has been investigated as part of the International Ocean Discovery Program. Onshore, some of the current project’s investigators have already documented a number of the existing conditions where sampling took place.

Map of the Costa Rica convergent margin showing the location of active volcanoes, previously investigated hot springs (with associated temperatures) and ODP/IODP archival cores. Credit: Josh Wood/DCO Engagement Team

Opportunity for new understanding
Carbon is stored in ocean sediments, as well as in Earth’s mantle and crust. Each of these “storage areas” serves as a carbon reservoir. Carbon flux is the term for carbon movement between reservoirs. Many questions exist about the influence of biological processes on carbon flux. This investigation will help scientists better predict how carbon moves in and out of Earth on a global basis and how that movement is related to biological processes.
Because this project is exploratory, it will improve what we know about how carbon moves, but also is offering vast opportunities for surprising new discoveries. Another unique aspect is that the lead investigators are early career scientists (within seven years of being awarded a PhD), who have aligned themselves with a strong collection of external collaborators, many of whom are leaders in their field. What this team learns will inform the field of deep carbon science for years to come.

Research Plan 

Volcanologist Tobias Fischer (University of New Mexico, USA) samples gases emitted from a sulfur-caked fumarole on Poás volcano in Costa Rica, one of the 15 volcanoes in DCO’s DECADE gas monitoring network. Credit: Raúl Mora-Amador and Carlos Ramírez U, University of Costa Rica.

The team visited 25 field sites over the course of 12 days: Poás, Turrialba, and Arenal volcanoes and springs along the Nicoya and Osa peninsulas. Costa Rican scientists will play integral roles in the logistic and scientific success of the field campaign, with Carlos Ramirez from the University of Costa Rica leading the charge. The local team also includes Gino Gonzalez from the University of Costa Rica, and J. Maarten de MoorMaria MartinezMonserrat Cascante, and Ricardo Sanchez from the Observatorio Vulcanológico Y Sismológico de Costa Rica, Universidad Nacional, Costa Rica  (OVSICORIO-UNA)). Together, the local and international team of investigators conducted different sampling protocols at each of the locations, as described below.
Going deeper: On site sampling
Principal Investigator Peter Barry (University of Oxford, UK) and collaborator Patrick Beaudry (Massachusetts Institute of Technology, USA) collected fluid and gas samples in the forearc and arc to distinguish biogenic, thermogenic, and abiotic carbon sources.  
Donato Giovanelli (Earth-Life Science Institute, Japan and Rutgers University, USA) and Karen Lloyd (University of Tennessee, USA) led a team of collaborators that includes Lloyd’s graduate student Katie Fullerton, as well as collaborator Heather Miller (Michigan State University, USA). They combined in situ measurements of biologically relevant geochemistry and metabolic activity with ex situ biochemical and molecular tools to investigate the functional and taxonomic diversity of the microbial community within sediments and fluids in the volcanic arc and forearc.
Daniel Hummer (Southern Illinois University, USA) and J. Marteen de Moor (Universidad Nacional, Costa Rica), Angelo Battaglia (Università degli Studi di Palermo, Italy), Giulio Bini (University of Florence, Italy), and Kayla Iocovino (Arizona State University, USA) measured the complete chemical composition of gases from actively degassing volcanoes using a combination of direct measurement and in situ sampling. Taryn Lopez (University of Alaska Fairbanks, USA) spearheaded this part of the sampling plan and was unable to join the team in the field, but will remain heavily involved in the project moving forward. 
Hummer and de Moor, with collaborators Esteban Gazel and Aristides Alfaro (Virginia Tech, USA),  sampled volcanic tephras (solid matter, such as ash, dust, and cinders, that is ejected into the air by an erupting volcano) from Turrialba, Poás, and Arenal volcanoes, which contain abundant olivine phenocrysts with melt and fluid inclusions.
Collaborator Stephen Turner  (Washington University in St. Louis, USA) used sophisticated analytical methods to track fluxes from the slab to the mantle wedge, helping to delineate volatile sources and the proportion of deeply recycled carbon. Kayla Iocovino is working to create a box model describing carbon flux at this convergent margin. 
Katie Pratt (University of Rhode Island, USA) documented the expedition, blogging from the field and photographing and filming the team in action. Videographers Marcus Lehmann, Brian Cimaglia, Russ Hollingsworth, and Tom Owens, also joined the expedition and are creating short films about this novel field investigation.
Additional collaborators not participating in the field, but involved in data and sample analysis, include Mustafa Yucel, Matt Schrenk, Shuhei Ono, Rosario Esposito, David Hilton, Christopher House, Amanda Martino, Elena Manini, Constantino Vitriani, Tomohiro Mochizuki, Mayukpo Nakagawa, and Francesco Regoli.
Since the sampling expedition is now complete, investigators are sharing samples and conducting additional analyses in many laboratories around the globe. The team expects to report out their results in spring 2018.  Check back here as the results unfold.

Expedition Scientists (Peter Barry)
University of Oxford, UK

Karen Lloyd
University of Tennessee, USA

Donato Giovannelli
Earth-Life Science Institute, Japan
and Rutgers University, USA

Daniel Hummer
Southern Illinois University, USA

Taryn Lopez
University of Alaska, USA

J. Maarten de Moor
Universidad Nacional, Costa Rica

Katie Pratt
University of Rhode Island, USA

Research Team

  • Aristides Alfaro
    Virginia Tech, USA

  • Joy Buongiorno
    University of Tennessee, USA

  • Monserrat Cascante
    OVSICORI-UNA, Costa Rica

  • Rosario Esposito
    University of California, Los Angeles, USA

  • Esteban Gazel
    Virginia Tech, USA

  • Maria Martinez
    OVSICORI-UNA, Costa Rica

  • Raúl Mora
    University of Costa Rica

  • Shuhei Ono
    Massachusetts Institute of Technology, USA

  • Rita Parai
    Washington University in St. Louis, USA

  • Carlos Ramirez
    University of Costa Rica, Costa Rica

  • Francesco Regoli
    Polytechnic University of Marche, Italy

  • Matt Schrenk
    Michigan State University, USA

  • Stephen Turner
    Washington University in St. Louis, USA

  • Lorena Uribe
    University of Costa Rica, Costa Rica

  • Mustafa Yucel
    Middle East Technical University, Turkey

  • José Zuñiga
    OVSICORI-UNA, Costa Rica


1 April 2018

Darlene Trew Crist, University of Rhode Island, USA 

Nine scientists from the original scientific party returned to Costa Rica to conduct additional sampling, mainly in new sites from the previous sampling expedition. The group is comprised of Peter Barry, Carlos Ramirez, Patrick Beaudry, Donato Giovannelli, Karen Lloyd, Kate Fullerton, Matt Schrenk, J. Maarten de Moor, and Stephen Turner.  They plan to spend 16 days in Costa Rica, adding to the richness of data already collected. Follow along on their journey on Twitter #subductCR.  

16 December 2017

Darlene Trew Crist, University of Rhode Island, USA 

The Biology Meets Subduction Team took advantage of their mutual attendance at AGU's Fall Meeting in New Orleans. After AGU, the Team extended their stay for another week to begin the process of assessing their results and writing papers. Just like their project, they took a non-traditional approach and shared a large AirBNB house, which allowed them to work for many more hours each day and accomplish a great deal over the week spent together. The team put forward a plan to write 13 papers from their expedition and submit three proposals to make further research possible. 

21 August 2017

Darlene Trew Crist, University of Rhode Island, USA 

A DCO-produced film about the field work conducted during the 12-day sampling program in Costa Rica was premiered at the 2017 Goldschmidt Film Festival in Paris, France. The film won first prize from among 92 submissions. The film will make its American premier in the fall 2017, after which it will be available for viewing and sharing by the DCO Science Network.  Stay tuned.

24 February 2017
Darlene Trew Crist, University of Rhode Island, USA 

Over a two-week span in February, 20 early career investigators sampled 25 different volcanic and hot spring sites in the Costa Rican volcanic arc.


A video that provides a bird's eye view of the expedition is here:
Some of the scientists explain their field work here:

14 February 2017
Darlene Trew Crist, University of Rhode Island, USA 

The team has arrived!  Daily reports on their progress can be found here

1 November, 2016
Katie Pratt, University of Rhode Island, USA

Turrialba’s eruption continues (November 2017), with columns of ash and gas up to 1km high. Credit: Gino Gonzáles-Ilama.

Members of the Biology Meets Subduction team are currently planning their field expedition. A team of approximately 25 scientists, led by the seven early career scientists who proposed the project, will head to Costa Rica on 11 February 2017.
The expedition will focus on the warm and hot springs of the Nicoya peninsula, as well as active volcanoes north of the capital San José. With Turrialba volcano currently erupting, the team is modifying their sampling route for safety reasons and to avoid travel disruptions.
The team is focused at the moment on finalizing personnel and ordering the necessary equipment for the field. They are also working with videographer David Fine to finalize plans for their short documentary.
Thanks to previous field campaigns by various team members in Costa Rica, contacts made during the 2014 DCO Early Career Scientist Workshop, and co-PI Maarten de Moor’s current position at the National University in Costa Rica, the team is already making huge progress in terms of logistical planning.

Further Reading

Aiuppa, A., Federico, C., Giudice, G., & Gurrieri, S. (2005). Chemical mapping of a fumarolic field: La Fossa crater, Vulcano island (Aeolian islands, Italy). Geophysical Research Letters, 32(13).

Andres, R. J., & Kasgnoc, A. D. (1998). A timeDaveraged inventory of subaerial volcanic sulfur emissions. Journal of Geophysical Research: Atmospheres, 103(D19), 25251-25261. Barker, C. E., & R. H. Goldstein. (1990). Fluid-inclusion technique for determining maximum temperature in calcite and its comparison to the vitrinite reflectance geothermometer. Geology, 18, 1003-1006.

Barry, P.H., Hilton, D.R., Halldórsson S. A., Hahm, D. and Marti, K. (2012) High precision nitrogen isotope measurements in oceanic basalts using a static triple collection noble gas mass spectrometry. Geology, Geophysics, and Geosystems (G-Cubed), (Technical Briefs) 13, Number 1.

Barry, P.H., Hilton, D.R., Fischer, T.P., de Moor, J.M., Mangasini, F, Ramirez, C.J., (2013) Helium and carbon isotope systematics of cold “mazuku” CO2 vents and hydrothermal gases and fluids from Rungwe Volcanic Province, southern Tanzania, Chemical Geology, 339, 141-156.

Barry, P. H., Hilton, D. R., Füri, E., Halldórsson, S. A., & Grönvold, K. (2014). Carbon isotope and abundance systematics of Icelandic geothermal gases, fluids and subglacial basalts with implications for mantle plume-related CO2 fluxes. Geochimica et Cosmochimica Acta, 134, 74-99.

Barry, P.H., Hilton, D.R., Day, J.M., Pernet-Fisher, J.F., Howarth, G.H., Magna, T., Agashev, A.M., Pokhilenko, N.P., Pokhilenko, L.N. and Taylor, L.A. (2015). Helium isotopic evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event. Lithos, 216, pp.73-80.

Barry, P.H., Lawson, M., Meurer, W.P., Warr, O., Mabry, J.C., Byrne, D.J., and Ballentine, C.J. Noble gases solubility models of hydrocarbon charge mechanisms in the Sleipner Vest methane field. Geochim. Cosmochim. Acta, In Review.

Benjamin, E. R., Plank, T., Wade, J. A., Kelley, K. A., Hauri, E. H., &  Alvarado, G. E. (2007). High water contents in basaltic magmas from Irazu volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 168, 68-92.

Bergfeld, D., Lewicki, J. L., Evans, W. C., Hunt, A. G., Revesz, K., & Huebner, M. (2013). Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012. US Geol. Surv. Sci. Invest. Rep, 5231, 20.

Beulig, F., T. Urich, M. Nowak, S. E. Trumbore, G. Gleixner, G. D. Gilfillan, K. E. Fjelland,

& K. Kusel. (2016). Altered carbon turnover processes and microbiomes in soils under long-term extremely high CO2 exposure. Nature Microbiology, 1: 1-9.

Bird, J. T., Baker, B. J., Probst, A. J., Podar, M., & Lloyd, K. G. Culture independent genomic comparisons reveal environmental adaptations for Altiarchaeales. Frontiers in Microbiology, Submitted.

Casadevall, T. J., Rose, W. I., Fuller, W. H., Hunt, W. H., Hart, M. A.,Moyers, J.L., Woods, D.C., Chuan, R.L. & Friend, J.P. (1984). Sulfur dioxide and particles in quiescent volcanic plumes from Poás, Arenal, and Colima volcanos, Costa Rica and Mexico. Journal of Geophysical Research: Atmospheres, 89(D6), 9633-9641.

Chiodini, G., Granieri, D., Avino, R., Caliro, S., Costa, A., Werner, C. (2005.) Carbon dioxide diffuse degassing and estimation of heat release from volcanic and hydrothermal systems, J Geophys Res Solid Earth 110:B08204, doi: 10.1029/2004JB003542

Clift, P., & Vannucchi, P. (2004). Controls on tectonic accretion versus erosion in subduction zones: Implications for the origin and recycling of the continental crust. Reviews of Geophysics,

Crossey, L. J., Karlstrom, K. E., Schmandt, B., Crow, R. R., Colman, D.R., Cron, B., Takacs- Vesbach, C.D., Dahm, C.N., Northup, D.E., Hilton, D.R. & Ricketts, J.W. (2016). Continental smokers couple mantle degassing and distinctive microbiology within continents. Earth and Planetary Science Letters, 435, 22-30.

Coleman, D. R., Garcia, J. R., Crossey, L. J., Karlstrom, K., JacksonDWeaver, O., & TakacsDVesbach, C. (2014). An analysis of geothermal and carbonic springs in the western United States sustained by deep fluid inputs.Geobiology, 12(1), 83-98.

D'Amore, F., & Panichi, C. (1980). Evaluation of deep temperatures of hydrothermal systems by a new gas geothermometer. Geochimica et Cosmochimica Acta, 44(3), 549-556.

Emerson, David, Emily J. Fleming, and Joyce M. McBeth. (2010) Iron-oxidizing bacteria: an environmental and genomic perspective. Annual review of microbiology, 64, 561-583.

DeMets, C. (2001). A new estimate for present day Cocos Caribbean plate motion: Implications for slip along the Central American volcanic arc.Geophysical Research Letters, 28(21), 4043-4046.

de Moor, J. M., A. Aiuppa, J. Pacheco, G. Avard, C. Kern, M. Liuzzo, M. Martinez, G. Giudice, and T. P. Fischer (2016). Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica, Earth and Planetary Science Letters, 442, 218-227. doi:210.1016/j.epsl.2016.1002.1056.

de Moor, J. M., A. Aiuppa, G. Avard H. Wehrmann, N. Dunbar C. Muller G. Tamburello G. Giudice, M. Liuzzo, R. Moretti, V. Conde, B. Galle. Turmoil at Turriala volcano (Costa Rica):

Degassing and eruptive behavior inferred from high-frequency gas monitoring, Journal of

Goephysical Research, In Review.

Edgcomb, V. P., Molyneaux, S. J., Boer, S., Wirsen, C. O., Saito, M., Atkins, M. S., Lloyd, K., & Teske, A. (2007). 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.

Fiebig, J., Chiodini, G., Caliro, S., Rizzo, A., Spangenberg, J., & Hunziker, J. C. (2004). Chemical and isotopic equilibrium between CO2 and CH4 in fumarolic gas discharges: generation of CH4 in arc magmatic-hydrothermal systems. Geochimica et Cosmochimica Acta, 68(10), 2321-2334.

Fiebig, J., Hofmann, S., Tassi, F., D'Alessandro, W., Vaselli, O., & Woodland, A. B. (2015). Isotopic patterns of hydrothermal hydrocarbons emitted from Mediterranean volcanoes. Chemical Geology, 396, 152-163.

Fischer, T.P., & Chiodini, G., (2015). Volcanic, magmatic and hydrothermal gases, in The

Encyclopedia of Volcanoes.

Fischer, T. P., Ramírez, C., Mora-Amador, R. A., Hilton, D. R., Barnes, J. D., Sharp, Z.D., Le Brun, M., de Moor, J.M., Barry, P.H., Füri, E. & Shaw, A. M. (2015). Temporal variations in fumarole gas chemistry at Poás volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 294, 56-70.

Freundt, A., Grevemeyer, I., Rabbel, W., Hansteen, T. H., Hensen, C., Wehrmann, H.,  & Frische, M. (2014). Volatile (H2O, CO2, Cl, S) budget of the Central American subduction zone. International Journal of Earth Sciences, 103(7), 2101-2127.

Füri, E., Hilton, D. R., Tryon, M. D., Brown, K. M., McMurtry, G. M., Brückmann, W., & Wheat, C. G. (2010). Carbon release from submarine seeps at the Costa Rica fore arc: Implications

for the volatile cycle at the Central America convergent margin. Geochemistry, Geophysics, Geosystems, 11(4).

Galle, B., Johansson, M., Rivera, C., Zhang, Y., Kihlman, M., Kern, C., Lehmann, T., Platt, U., Arellano, S. & Hidalgo, S. (2010). Network for Observation of Volcanic and Atmospheric Change (NOVAC)—A global network for volcanic gas monitoring: Network layout and instrument description. Journal of Geophysical Research: Atmospheres, 115(D5).

Giggenbach, W. F. (1987). Redox processes governing the chemistry of fumarolic gas discharges from White Island, New Zealand. Applied Geochemistry, 2(2), 143-161.

Gorman, P. J., Kerrick, D. M., & Connolly, J. A. D. (2006). Modeling open system metamorphic decarbonation of subducting slabs. Geochemistry, Geophysics, Geosystems, 7(4).

Han, X., Suess, E., Sahling, H., & Wallmann, K. 2004. Fluid venting activity on the Costa

Rica margin: new results from authigenic carbonates. International Journal of Earth Science, 93, 596-611.

Harvey, J., Savov, I. P., Agostini, S., Cliff, R. A., Walshaw, R. (2014) Si-metasomatism in serpentinized peridotite: The effects of talc-alteration on strontium and boron isotopes in abyssal serpintinites from Hole 1268a, ODP Leg 209. Geochemica Cosmochimica Acta, 126, 30-48.

Hilton, D. R., Fischer, T. P., & Marty, B. (2002). Noble gases and volatile recycling at subduction zones. Reviews in mineralogy and geochemistry, 47(1), 319-370.

Hilton, D. R., Ramirez, C. J., Mora-Amador, R., Fischer, T. P., Fueri, E., Barry, P. H., & Shaw, A. M. (2010). Monitoring of temporal and spatial variations in fumarole helium and carbon dioxide characteristics at Poás and Turrialba volcanoes, Costa Rica (2001-2009). Geochemical Journal, 44(5), 431-440.

Hoehler, T. M., and B. B. Jorgensen. (2013). Microbial life under extreme energy limitation.Nature Reviews Microbiology. 11:83-94.


Ishikawa, T. & Nakamura, E. (1993) Boron isotope systematics of marine sediments. Earth and Planetary Science Letters, 117, 567-580.

Kelemen, P. B., & Manning, C. E. (2015). Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up. Proceedings of the National Academy of Sciences, 112(30), E3997-E4006.

Kimura, G., et al. (Eds.) (1997). Proceedings of the Ocean Drilling Program, Initial Reports, vol. 170, Ocean Drill. Program, College Station, Tex.

Krabbenhoft, A., Eisenhauer, A., Bohm, F., Vollstaedt, H., Fietzke, J., Liebetrau, V., Augustin, N., Peucker-Ehrenbrink, B., Muller, M. N., Horn, C., Hansen, B. T., Nolte, N., Wallmann, K. (2010). Constraining the marine strontium budget with natural strontium isotope fractionations (87Sr/86Sr*, δ88/86Sr) of carbonates, hydrothermal solutions and river waters. Geochimica Cosmochimica Acta, 74, 4097-4109.

Lloyd, K. G., L. Schreiber, D. G. Petersen, K. Kjeldsen, M. A. Lever, A. D. Steen, R. Stepanauskas, M. Richter, S. Kleindienst, S. Lenk, A. Schramm, & B. B. Jørgensen. (2013). Predominant archaea in marine sediments degrade detrital proteins. Nature, 496: 215-219.

Lloyd, K. G., Edgcomb, V. P., Molyneaux, S. J., Boer, S., Wirsen, C. O., Atkins, M. S., & Teske, A. (2005). Effects of dissolved sulfide, pH, and temperature on growth and survival of marine hyperthermophilic archaea. Applied and Environmental Microbiology, 71: 6383-6387.

Newman, S., & Lowenstern, J. B. (2002). VolatileCalc: a silicate melt–H2O–CO2  solution model written in Visual Basic for Excel. Computers & Geosciences, 28(5), 597-604.

Ono, S., Wang, D. T., Gruen, D. S., Sherwood Lollar, B., Zahniser, M. S., McManus, B. J., & Nelson, D. D. (2014). Measurement of a doubly substituted methane isotopologue, 13CH3D, by tunable infrared laser direct absorption spectroscopy. Analytical chemistry, 86(13), 6487-6494.

Orsi, W. D., Edgcomb, V. P., Christman, G. D., & Biddle, J. B. (2013). Gene expression in the deep biosphere. Nature, 499: 205-208.

Platt, U., & Stutz, J. (2008). Differential absorption spectroscopy, pp. 135-174. Springer Berlin Heidelberg.

Ranero, C. R., and R. von Huene (2000). Subduction erosion along the Middle America convergent margin. Nature, 404(6779), 748–752.

Ranero, C. R., Grevemeyer, I., Sahling, H., Barckhausen, U., Hensen, C., Wallmann, K., ... & McIntosh, K. (2008). Hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis. Geochemistry, Geophysics, Geosystems, 9(3).

Reeburgh, W. (2007). Ocean methane biogeochemistry. Chemical Reviews, 107: 486-513. Rowe, G L., Brantley, S. L., Fernandez, J. F., Borgia, A. (1995) The chemical and hydrologic structure of Poás volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 64(3), 233-267.

Sano, Y., & Marty, B. (1995). Origin of carbon in fumarolic gas from island arcs. Chemical

Geology, 119(1), 265-274.

Shaw, A. M., Hilton, D. R., Fischer, T. P., Walker, J. A., & Alvarado, G. E. (2003). Contrasting He–C relationships in Nicaragua and Costa Rica: insights into C cycling through subduction zones. Earth and Planetary Science Letters, 214(3), 499-513.

Shaw, A. M., Hilton, D. R., Fischer, T. P., Walker, J. A., de Leeuw, G. A. M. (2006). Helium isotope variations in mineral separates from Costa Rica and Nicaragua: Assessing crustal contributions, timescale variations and diffusion-related mechanisms. Chemical Geology, 230, 124-139.

Shock, E. L., & Boyd, E. S. (2015). Principles of Geobiochemistry. Elements, 11(6), 395-401.

Solden, L., Lloyd, K. G., & Wrighton, K. (2016). The bright side of microbial dark matter: lessons learned from the uncultivated majority. Current Opinion in Microbiology, 31: 217-226.

Spinelli, G. A., and Saffer, D. M.  (2004). Along-strike variations in underthrust sediment dewatering on the Nicoya margin, Costa Rica related to the updip limit of seismicity, Geophysical Research Letters, 31, L04613.

Spinelli, G. A., and Underwood,  M. B.  (2004). Character of sediments entering the Costa Rica subduction zone: Implications for partitioning of water along the plate interface, Isl. Arc, 13(3), 432–451.

Stern, R. J. (2002). Subduction zones. Reviews of geophysics, 40(4).

Sterner, S. M., & Bodnar, R. J. (1984). Synthetic fluid inclusions in natural quartz I. Compositional types synthesized and applications to experimental geochemistry. Geochimica et Cosmochimica Acta, 48(12), 2659-2668.

Thomson, A. R., Kohn, S. C., Bulanova, G. P., Smith, C. B., Araujo, D., & Walter, M. J. (2014). Origin of sub-lithospheric diamonds from the Juina-5 kimberlite (Brazil): constraints from carbon isotopes and inclusion compositions. Contributions to Mineralogy and Petrology, 168(6), 1-29.

Thomazo, C., D. L. Pinti, V. Busigny, M. Ader, K. Hashizume, P. Philippot. (2009). Biological activity and the Earth’s surface evolution: Insights from carbon, sulfur, nitrogen and iron stable isotopes in the rock record. C. R. Palevol. 8: 665-678.

Vannucchi, P., K. Ujiie, K. Stroncik, N. Malinverno, and the Expedition 334 scientists. (2012). Expedition 334 Summary. Proceedings of the Integrated Ocean Drilling Program. Vol. 334.

Vannucchi, P., and Tobin, H. (2000). Deformation structures and implications for fluid flow at the Costa Rica convergent margin, ODP Sites 1040 and 1043, Leg 170, Journal of Structural Geology, 22(8), 1087–1103

von Huene, R. V., Ranero, C. R., Weinrebe, W., & Hinz, K. (2000). Quaternary convergent margin tectonics of Costa Rica, segmentation of the Cocos Plate, and Central American volcanism. Tectonics, 19(2), 314-334.

Wade, J. A., Plank, T., Melson, W. G., Soto, J. G., Hauri, E. H. (2006). The volatile content of magmas from Arenal volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 157, 94-120.

Wehrmann, H., Hoernle, K., Portnyagin, M., Wiedenbeck, M., & Heydolph, K. (2011). Volcanic CO2 output at the Central American subduction zone inferred from melt inclusions in olivine crystals from mafic tephras. Geochemistry, Geophysics, Geosystems, 12(6).

Young, E. D., Rumble, D., Freedman, P., Mills, M. (2016) A large-radius high-mass- resolution multiple-collector isotope ratio mass spectrometer for analysis of rare isotopologues of O2, N2, CH4 and other gases. International Journal of Mass Spectrometry, 401, 1-10.

Zimmer, M. M., T. P. Fischer, D. R. Hilton, G. E. Alvarado, Z. D. Sharp., J. A. Walker. (2004). Nitrogen systematics and gas fluxes of subduction zones: Insights from Costa Rica arc volatiles. Geochemistry Geophysics Geosystems, 5(5), 1-19.

Header image: Overlooking Turrialba volcano in Costa Rica. Credit: Katie Pratt