News Release

Imperfect diamonds paved road to historic Deep Earth discoveries

Materials trapped inside diamonds offer clues to life's origin; suggest oceans' worth of water hidden in Deep Earth

Peer-Reviewed Publication

Terry Collins Assoc

Deep Carbon Observatory -- A Decade of Discovery

video: Based at the Carnegie Institution for Science in Washington DC, with $50 million in core support from the Alfred P. Sloan Foundation multiplied many times by additional investments worldwide, 1,200 multidisciplinary researchers from 55 nations explored Earth's fundamental history and workings, including:

  • How carbon moves between Earth's interior, surface and atmosphere
  • The limits to Earth's deep microbial life
  • Where Earth's deep carbon came from, how much exists and in what forms
  • How life began

They investigated Earth's interior in several ways, producing 1,400 peer-reviewed papers while pursuing 268 projects.

(Selected clips available to media on request) view more 

Credit: Deep Carbon Observatory

Deep Carbon Observatory highlights 10 top discoveries to celebrate a 10-year global investigation of Earth's largest, least-known ecosystem; 1,200 scientists from 55 nations, 1,400 peer-reviewed papers

Washington DC - Thousands of diamonds, formed hundreds of kilometers deep inside the planet, paved the road to some of the 10-year Deep Carbon Observatory program's most historic accomplishments and discoveries, being celebrated Oct. 24-26 at the US National Academy of Sciences.

Unsightly black, red, green, and brown specks of minerals, and microscopic pockets of fluid and gas encapsulated by diamonds as they form in Deep Earth, record the elemental surroundings and reactions taking place within Earth at a specific depth and time, divulging some of the planet's innermost secrets.

Hydrogen and oxygen, for example, trapped inside diamonds from a layer 410 to 660 kilometers below Earth's surface, reveal the subterranean existence of oceans' worth of H2O -- far more in mass than all the water in every ocean in the surface world.

This massive amount of water may have been brought to Deep Earth from the surface by the movement of the great continental and oceanic plates which, as they separate and move, collide with one another and overlap. This subduction of slabs also buries carbon from the surface back into the depths, a process fundamental to Earth's natural carbon balance, and therefore to life.

Knowledge of Deep Earth's water content is critical to understanding the diversity and melting behaviors of materials at the planet's different depths, the creation and flows of hydrocarbons (e.g. petroleum and natural gas) and other materials, as well as the planet's deep subterranean electrical conductivity.

By dating the pristine fragments of material trapped inside other super-deep diamond "inclusions," DCO researchers could put an approximate time stamp on the start of plate tectonics -- "one of the planet's greatest innovations," in the words of DCO Executive Director Robert Hazen of the Carnegie Institution for Science. It started roughly 3 billion years ago, when the Earth was a mere 1.5 billion years old.

Diamond research accelerated dramatically thanks to the creation of DCO's global network of researchers and led to some of the program's most intriguing discoveries and achievements.

Diamonds from the deepest depths, often small with poor clarity, are not generally used as gemstones by Tiffany's but are amazingly complex, robust and priceless in research. Inclusions offered DCO scientists samples of minerals that exist only at extreme high subterranean pressure, and suggested three ways in which diamonds form.

While as many as 90% of analyzed diamonds were composed of carbon scientists expected in the mantle, some "relatively young" diamonds (up to a few hundred million years old) appear to include carbon from once-living sources; in other words, they are made of carbon returned to Deep Earth from the surface world.

Diamonds also revealed unambiguous evidence that some hydrocarbons form hundreds of miles down, well beyond the realm of living cells: abiotic energy.

Unravelling the mystery of deep abiotic methane and other energy sources helps explain how deep life in the form of microbes and bacteria is nourished, and fuels the proposition that life first originated and evolved far below (rather than migrating down from) the surface world.

Diamonds also enabled DCO scientists to simulate the extreme conditions of Earth's interior.

DCO's Extreme Physics and Chemistry community scientists used diamond anvil cells -- a tool that can squeeze a sample tremendously between the tips of two diamonds, coupled with lasers that heat the compressed crystals -- to simulate deep Earth's almost unimaginable extreme temperatures and pressures.

Using a variety of advanced techniques, they analyzed the compressed samples, identified 100 new carbon-bearing crystal structures and documented their intriguing properties and behaviors.

The work provided insights into how carbon atoms in Deep Earth "find one another," aggregate, and assemble to form diamonds and other material.

Development of new materials; potential carbon capture and storage strategies

DCO's discoveries and research are important and applicable in many ways, including the development of new materials and potential carbon capture and storage strategies.

DCO scientists are studying, for example, how the natural timescale for sequestration of carbon might be shortened.

The weathering of and microbial life inside Oman's Samail Ophiolite -- an unusual, large slab pushed up from Earth's upper mantle long ago -- offers a tutorial in nature's carbon sequestration techniques, knowledge that might help offset carbon emissions caused by humans.

In Iceland, another DCO natural sequestration project, CarbFix, involves injecting carbon-bearing fluids into basalt and observing their conversion to solids.

A Decade of Discovery

Hundreds of scientists from around the world meet in Washington DC Oct. 24 to 26 to share and celebrate results of the wide-ranging, decade-long Deep Carbon Observatory -- one of the largest global research collaborations in Earth sciences ever undertaken (venue, program: Deep Carbon 2019: Launching the Next Decade of Deep Carbon Science,

With its Secretariat at the Carnegie Institution for Science in Washington DC, and $50 million in core support from the Alfred P. Sloan Foundation, multiplied many times by additional investment worldwide, a multidisciplinary group of 1,200 researchers from 55 nations worked for 10 years in four interconnected scientic "communities" to explore Earth's fundamental workings, including:

  • How carbon moves between Earth's interior, surface and atmosphere
  • Where Earth's deep carbon came from, how much exists and in what forms
  • How life began, and the limits -- such as temperature and pressure -- to Earth's deep microbial life

They met the challenge of investigating Earth's interior in several ways, producing 1,400 peer-reviewed papers while pursuing 268 projects that involved, for example:

  • Studying diamonds, volcanoes, and core samples obtained by drilling on land and at sea
  • Conducting lab experiments to mimic the extreme temperatures and pressures of Earth's interior, and through theoretical modeling of carbon's evolution and movements over deep time, and
  • Developing new high tech instruments

DCO scientists conducted field measurements in remote and inhospitable regions of the world: ocean floors, on top of active volcanoes, and in the deserts of the Middle East.

Where instrumentation and models were lacking, DCO scientists developed new tools and models to meet the challenge. Throughout these studies, DCO invested in the next generation of deep carbon researchers, students and early career scientists, who will carry on the tradition of exploration and discovery for decades to come.

Key discoveries during the 10-year Deep Carbon Observatory program

In addition to insights from its diamond research above, the program's top discoveries include:

The deep biosphere is one of Earth's largest ecosystems

Life in the deep subsurface totals 15,000 to 23,000 megatonnes (million metric tons) of carbon, about 250 to 400 times greater than the carbon mass of all humans. The immense Deep Earth biosphere occupies a space nearly twice as large as all the world's oceans.

DCO scientists explored how microbes draw sustenance from "abiotic" methane and other energy sources -- fuel that wasn't derived from biotic life above.

If microbes can eek out a living using chemical energy from rocks in Earth's deep subsurface, that may hold true on other planetary bodies.

This knowledge about the types of environments that can sustain life, particularly those where energy is limited, can guide the search for life on other planets. In the outer solar system, for example, energy from the sun is scarce, as it is in Earth's subsurface environment.

DCO researchers also found the deepest, lowest-density, and longest-lived subseafloor microbial ecosystem ever recorded and changed our understanding of the limits of life at extremes of pressure, temperature, and depth.

Rocks and fluids in Earth's crust provide clues to the origins of life on this planet, and where to look for life on others

DCO scientists found amino acids and complex organic molecules in rocks on the seafloor. These molecules, the building blocks of life, were formed by abiotic synthesis and had never before been observed in the geologic record.

They also found pockets of ancient salty fluids rich in hydrogen, methane, and helium many kilometers deep, providing evidence of early, protected environments capable of harboring life.

Abiotic methane forms in the crust and mantle of Earth

When water meets the ubiquitous mineral olivine under pressure, the rock reacts with oxygen atoms from the H2O and transforms into another mineral, serpentine -- characterized by a scaly, green-brown, snake skin-like appearance.

This process of "serpentinization" leads to the formation of "abiotic" methane in many different environments on Earth. DCO scientists developed and used sophisticated analytical equipment to differentiate between biotic (derived from ancient plants and animals) and abiotic formation of methane.

DCO field and laboratory studies of rocks from the upper mantle document a new high-pressure serpentinization process that produces abiotic methane and other forms of hydrocarbons.

The formation of methane and hydrocarbons through these geologic, abiotic processes provides fuel and sustenance for microbial life.

Atmospheric CO2 has been relatively stable over the eons but huge, occasional catastrophic carbon disturbances have taken place

DCO scientists have reconstructed Earth's deep carbon cycle over eons to the present day. This new, more complete picture of the planetary ingassing and outgassing of carbon shows a remarkably stable system over hundreds of millions of years, with a few notable episodic exceptions.

Continental breakup and associated volcanic activity are the dominant causes of natural planetary outgassing. DCO scientists added to this picture by investigating rare episodes of massive volcanic eruptions and asteroid impacts to learn how Earth and its climate responds to such catastrophic carbon disturbances.

Plate tectonics modeling using DCO's new GPlates platform made it possible to reconstruct the Earth's carbon cycle through geologic time.

(Watch a 32-second animation of Earth's continental and oceanic plates in motion since the Jurassic period:

Much of the carbon outgassed from Deep Earth seeps from fractures and faults unassociated with eruptions

Volcanoes and volcanic regions outgas carbon dioxide (CO2) into the ocean / atmosphere system at a rate of 280-360 megatonnes per year. This includes both emissions during volcanic eruptions and degassing of CO2 out of diffuse fractures and faults in volcanic regions worldwide and the mid-ocean ridge system.

Human activities, such as burning fossil fuels, are responsible for about 100 times more CO2 emissions than all volcanic and tectonic region sources combined.

The changing ratio of CO2 to SO2 emitted by volcanoes may help forecast eruptions

The volume of outgassed CO2 relative to SO2 increases for some volcanoes days to weeks before an eruption, raising the possibility of improved forecasting and mitigating danger to humans.

DCO researchers measured volcanic outputs around the globe. Italy's Mount Etna, for example, one of Earth's most active volcanoes, typically spewed 5 to 8 times more CO2 than usual about two weeks before a large eruption.

Fluids move and transform carbon deep within Earth

Experiments and new theoretical work led to a revolutionary new DCO model of water in deep Earth and the discovery that diamonds can easily form through water-rock interactions involving organic and inorganic carbon.

This model predicted the changing chemistry of water found in fluid inclusions in diamonds and yields new insights into the amounts of carbon and nitrogen available for return to Earth's atmosphere over deep time.

DCO scientists also discovered that the solubility of carbon-bearing minerals, including carbonates, graphite, and diamond, is much higher than previously thought in water-rock systems in the mantle.

31 new carbon-bearing minerals found in four years

After cataloguing known carbon-bearing minerals at Earth's surface, their composition and where they are found, DCO researchers discovered statistical relationships between mineral localities and the frequency of their occurrence. With that model they predicted 145 yet-to-be-discovered species and in 2015 challenged citizen scientists to help find them.

Of the 31 new-to-science minerals turned up during the Carbon Mineral Challenge, two had been predicted, including triazolite, discovered in Chile and thought to have derived in part from cormorant guano. Photo below.

Meanwhile, scientists led by DCO Executive Director Robert Hazen, established an entirely new mineral classification system.

Through experiment and observation, DCO scientists discovered new forms of carbon deep in Earth's mantle, shedding new light on the carbon "storage capacity" of the deep mantle, and on the role of subduction in recycling surface carbon back to Earth's interior.

Studies also cast new light on the record of major changes in our planet's history such as the rise of oxygen and the waxing and waning of supercontinents.

Two-thirds of Earth's carbon may be in the iron-rich core

DCO research suggests that two-thirds or more of Earth's carbon may be sequestered in the core as a form of iron carbide. This "hidden carbon" brings the total carbon content of Earth closer to what is observed in the Sun and helps us to understand the origin of Earth's carbon from celestial material.



"In 2009, I believed in the existence of lots of non-fossil methane and in the deep origin of life, and the Deep Carbon Observatory has produced important evidence for these hypotheses."
Jesse Ausubel, The Rockefeller University; Science Advisor, Alfred P. Sloan Foundation, USA

"DCO scientists invented new instruments to monitor and measure carbon from volcanoes, revealing promising new ways to forecast eruptions and new estimates for how much carbon is outgassed from volcanoes. The DCO program is a testament to what becomes possible when a group of creative international scientists come together to understand the mysteries of our planet."
Marie Edmonds, University of Cambridge, UK

"It is only by admitting that one person cannot understand everything that we have made great strides in understanding the dynamics of the whole planets carbon cycle. Carbon is omnipresent and mobile throughout the Earth system, and the entire Cosmos. This makes it impossible for one scientist to understand carbon geochemistry, due to the enormity of the system in space, and through deep time. The DCO has encouraged and enabled people from all over the world to side-step the boundaries which commonly divide and define scientists within the rigid framework of classic disciplines. Only because of our individual admission of inherent ignorance have we been able to advance humanity's collective understanding of one of the most crucial elements to life. We are now getting closer to seeing the depth of the biosphere, the deepest realms of Earth's inaccessible interior, and we now know that Earth's carbon is a cosmic cocktail sourced from across the entire Solar System."
Sami Mikhail, University of St Andrews, UK

"The scientific secrets diamonds capture and deliver when they surface represent priceless 'windows' into the storage and transport of deep carbon over billions of years, yielding clues to their origins and to the workings of nature deep inside the Earth."
Steven Shirey, Carnegie Institution for Science, Washington DC

"The decadal research program of the Deep Carbon Observatory has put early career scientists front and centre, highlighting the long-term vision of building a vibrant and interdisciplinary community to tackle the big challenges of studying present-day and deep-time Earth processes."
Sabin Zahirovic, University of Sydney, Australia

"The Deep Carbon Observatory has created unprecedented cross-disciplinary research opportunities within a global community of scientists eager to discover the secrets of the carbon hidden in the interior of the Earth. Working together across the classical boundaries has led to the discovery of a whole range of hydrocarbons forming at depth and that could feed the subsurface biosphere."
Isabelle Daniel, Université Claude Bernard Lyon 1, France

"The Deep Carbon Observatory is the seed from which decades of future discoveries in deep carbon science will grow."
Catherine McCammon, Bayerisches Geoinstitut, Germany

Related DCO news releases

Life in Deep Earth Totals 15 to 23 Billion Tonnes of Carbon--Hundreds of Times More than Humans

Scientists quantify global volcanic CO2 venting; estimate total carbon on Earth

Rewriting the Textbook on Fossil Fuels

Big Data Points Humanity to New Minerals, New Deposits

First-Ever Catalog of 208 Human-Caused Minerals Bolsters Argument to Declare 'Anthropocene Epoch'

All releases

Future of the Deep Carbon Observatory

The Deep Carbon Observatory launched in 2009 with an ambitious plan to understand how carbon inside Earth--deep carbon--contributes to and affects the global carbon cycle. Carbon is one of the most important elements of our planet: carbon-based fuels provide much of our energy; carbon is an essential element of life; and excess carbon in our atmosphere presents one of the greatest planetary challenges of our time. The amount of carbon in the easily accessible surface environment, however, is only a tiny fraction of the carbon in Earth. Before DCO, remarkably little was known about the physical, chemical, and biological properties of Earth's deep carbon.

More than 1400 resulting peer-reviewed papers (available in a searchable database:, five books, and seven special issue journals shed light on the quantities, movements, forms, and origins of deep carbon -- openly available data that will keep future deep carbon scientists busy for the next decade and beyond.

In the wake of DCO a number of international projects related to deep carbon science have been established:

The Institut du Physique de Globe du Paris will serve as a new headquarters for this global community of deep carbon scientists as they pursue existing and new investigations, with the support of ongoing grants from NASA, the US National Science Foundation, the German Research Foundation, the Canadian Institute for Advanced Research, and other institutions.

Future deep carbon scientists will have many scientific questions to tackle, including the form in which carbon was first delivered to Earth, and when, and how different Earth might look today if the handful of past carbon catastrophes had not taken place, and many others.

DCO products

Members of the DCO community shared what they learned about the deep carbon cycle through articles in peer-reviewed journals, books, and special issues of journals. These include the following:


Deep Carbon: Past to Present is an edited volume that conveys what this international community of deep carbon scientists has learned over the last decade. Edited by Beth N. Orcutt, Isabelle Daniel, and Rajdeep Dasgupta. Cambridge University Press, October 2019.

Symphony in C: and the Evolution of (Almost) Everything explores carbon's multi-faceted characteristics in four movements - Earth, Air, Fire, and Water. Authored by Robert M. Hazen. W.W. Norton & Company, June 2019. Of interest: British composer David Earl wrote a symphony inspired by the concepts in Symphony in C. The Royal Scottish National Orchestra is performing the symphony on 24 October, and a recording of its performance will be available later this year.

Carbon in Planetary Interiors is a special AGU Monograph providing a compilation of new findings by DCO's Extreme Physics and Chemistry community about carbon in minerals, melts, and fluids at extreme conditions of planetary interiors and brings together emerging insights into carbon's forms, transformations and movements. Edited by Craig Manning, Wendy Mao, and Jung-Fu Lin. American Geophysical Union, October 2019.

A History of Deep Carbon Science from Crust to Core is a forthcoming historical account of deep carbon science from the 1400s to the present. Authored by Simon Mitton. Cambridge University Press, forthcoming in December 2019.

Carbon in Earth is the first compilation of new findings about the quantities, movements, forms, and origins of deep carbon within Earth's interior. Edited by Robert Hazen, John A. Baross and Adrian Jones. Reviews in Mineralogy and Geochemistry, 2013.

Special issue journals

A special Nature Collection of articles on deep carbon science, to be published on 21 October.

American Mineralogist - A special issue of American Mineralogist features the five most important carbon-related reactions on Earth, prompted by a DCO workshop in March 2018, where scientists from a variety of disciplines came together to discuss the question of which reactions are most critical to life on Earth. The resulting choices and their importance are reported in "Earth in Five Reactions: A Deep Carbon Perspective." (cite as: Li J, Redfern SAT, Giovannelli D, eds. (2019) Earth in Five Reactions: A Deep Carbon Perspective. Special issue, American Mineralogist)

Elements - This special issue titled "Catastrophic Perturbations to Earth's Carbon Cycle," focuses on catastrophic events in Earth's history and their impact on the carbon cycle. It, too, was prompted by a DCO workshop held in September 2018 to assure that catastrophic perturbations were accounted for in quantifying the deep carbon cycle. (cite as: Edmonds M, Jones A, Suarez C, eds. (2019) Catastrophic Perturbations to Earth's Carbon Cycle. Special issue, Elements)

Engineering - This is a collection of papers on "Deep Matter and Energy," which highlight the role of deep volatiles in mediating major Earth processes and spans a broad range of deep carbon science. It contains papers from a joint meeting of the Chinese Academy of Engineering and DCO, attended by 170 scientists from nine nations (cite as: Mao H-K, Sun C, eds. (2019) Deep Matter and Energy. Special issue, Engineering 5:3)

Frontiers Research Topic (x2) - A "Research Topic on Deep Carbon" in Frontiers shares new insights in deep carbon science from across the DCO Science Network. Forty-nine scientists contributed to the collection. (cite as: Daniel I, Zahirovic S, Bower DJ, Cardace D, Ionescu A, Mikhail S, Pistone M, eds. (2019) Research Topic on Deep Carbon. Special issue, Frontiers)

A second Frontiers Research topic focuses on contributions to deep carbon science made by DCO early career scientists, who represent the future of deep carbon science. This collection embodies their innovative ideas, non-traditional working schemes, and demonstrates the success of bringing a globally interconnected perspective to the scientific community. This issue also highlights work from DCO sponsored early career scientists workshops and DCO summer schools. (cite as Giovanelli D, Black BA, Cox AD, and Sheik CS, eds (2017) Research Topic on Deep Carbon in Earth: Early Career Scientist Contributions to the Deep Carbon Observatory. Special issue, Frontiers.)

G-Cubed - A special issue of Geochemistry, Geophysics, Geosystems (G-Cubed) focuses on advances in the field of deep carbon degassing, specifically on new understanding of carbon degassing through volcanoes and active tectonic regions. (cite as: Fischer T, Edmonds M, Aiuppa A, eds. (2019) Carbon Degassing Through Volcanoes and Active Tectonic Regions. Special issue, Geochemistry, Geophysics, Geosystems)

Journal of the Geological Society of London - This is a thematic set of articles on the "Carbon forms, paths, and processes in the Earth," derived from lectures presented at the Lake Como School in Como, Italy in October 2017. (cite as: Frezzotti ML, Villa IM, eds. (2019) Carbon Forms, Paths, and Processes in the Earth. Special issue, Journal of the Geological Society of London 176)

Modeling and Visualization

DCO scientists created modeling and visualization approaches that enable scientists to see and manipulate data in new ways. Some specific examples include:

EarthByte: The EarthByte group at the University of Sydney, Australia, created a virtual plate tectonic deep carbon laboratory, which revolutionized the study of mantle-crust-atmosphere interactions over deep time. EarthByte DCO scientists have used this platform, a series of videos reconstructing plate tectonic activity over time, to reconstruct the CO2 flux in different magmatic settings and simulated hydrogen flux produced by serpentinization of the seafloor over geologic time.

Virtual Reality: DCO helped scientists integrate virtual reality into their research so they can visualize data in new ways, which allows them to manipulate data in three dimensions and conduct virtual experiments. Three specific applications were developed making it possible for scientists to work virtually with mineral networks to see how minerals interact and co-locate with each other, visualize volcanic plumes, and construct and manipulate molecules to show the structure of melts, carbon degassing and other geologic processes.

MELTS/DEW Model DCO scientists developed the first integrated thermodynamic model of the magma-fluid system, making it possible to predict how carbon moves between solid, liquid, and fluid phases in response to temperature and pressure inside Earth.

E3- Earthquakes, Eruptions, and Emissions - DCO supported work to help create an app, developed by the Smithsonian Institution using its data and from the US Geological Survey, that provides open access to 50+ years of data on quakes, eruptions, and related emissions and shows the intimate ties between volcanoes and earthquakes.


Individual diamonds can have a long, complex, episodic growth history spanning billions of years. By studying tell-tale radioactive elements in their inclusions, some have been dated to 3 billion years and older. At right, shades and shapes record the episodes through which this stone, the Picasso diamond, grew. Download at

Blue boron-bearing diamonds are the world's most valuable and perhaps the most deeply-derived, estimated to originate around or below 660 km depth. Boron, seen as black spots in this 0.03 carat diamond, offer evidence of the subduction of slabs from the ocean floor into deep earth. Photo: Evan M. Smith/GIA. Download at

Inclusions, material trapped inside diamonds as they form, such as the red garnet seen in this photo, provide windows into Earth's inner workings. Photo credit: Stephen Richardson, University of Cape Town, South Africa. Download at

One of 31 new carbon-bearing minerals discovered during the DCO's Carbon Mineral Challenge, triazolite was found in Chile. It thought to have derived in part from cormorant guano. See also Photo credit: Joy Desor, Mineralanalytik Analytical Services. Download at

DCO scientists (at left, Lasse Ahonen, right, Riikka Kietäväinen, both of the Geological Survey of Finland) studied samples collected in challenging environments ranging from deep within Earth to below the ocean floor to the summit of active volcanoes. Here, scientists retrieve fluid samples from the Pyhäsalmi Mine in Finland. Credit: Arto Pullinen, GTK, Finland. Download at

Scott Nowicki, University of New Mexico, USA, member of an international team of DCO scientists, measured for the first time volcanic gases at Manam and Rabaul volcanoes in Papua New Guinea, using state-of-the-art unmanned aerial vehicles. Credit: Tobias Fischer, University of New Mexico, USA Download at

DCO field work spanned the globe, often involving collaborators from more than one of DCO's scientific communities. Shown here is sampling in Costa Rica as part of DCO's Biology Meets Subduction project, which involved early career scientists from all four communities. At left, Donato Giovannelli, University of Naples "Federico II," Italy; at right Kayla Iacovino, NASA Johnson, USA). Credit: Katie Pratt/Deep Carbon Observatory. Download at

To address the technological difficulties in retrieving deep-sea samples, DCO supported the development of PUSH50, a device that maintains deep-sea samples at high pressure so they can be recovered under in situ deep-sea conditions and studied in the laboratory without decompression. Credit: Hervé Cardon, Science for Clean Energy, CNRS, Lyon, France. Download at

DCO developer Edward Young, centre, and colleagues created the Panorama mass spectrometer at the University of California, Los Angeles, USA, to perform cutting-edge analysis of methane isotopologues that may be used to discriminate abiotic methane. Credit: Darlene Trew Crist/Deep Carbon Observatory

Download at

DCO scientists Laura Crispini (left), University of Genoa and Peter Kelemen, Lamont Doherty Earth Observatory, USA, took park in the International Continental Drilling Program's Oman Drilling Project to investigate natural CO2 sequestration through weathering and the microbes living inside the Samail Ophiolite. Credit: Darlene Trew Crist/Deep Carbon Observatory. Download at

The International Ocean Discovery Program (IODP) helped many DCO scientists collect samples and measurements critical to investigating the deep, subseafloor microbiome. Shown here is a rock drill used for the first time in the history of the program during expedition 357 to the Atlantis Massif on the Mid-Atlantic Ridge. Credit: ECORD/IODP. Download at

DCO scientists measured carbon dioxide emissions from more than 30 of the world's most prolific gas-emitting volcanoes and provided a new estimate of the total flux of carbon from volcanic outgassing. In photo: Tobias Fischer, University of New Mexico, USA. Credit: Carlos Ramirez Umana, Servicio Geologic Ambiental, Costa Rica. Download at

Volcanic eruptions bring diamonds to the surface. These "super-deep" diamonds were found in the Juina area of Brazil and grew at depths of depths of 660 kilometers or more in the mantle. The diamonds contain a range of inclusions of rare mantle minerals, some never previously observed in their natural state. Credit: Graham Pearson, University of Alberta, Canada Download at

The GPlates software ( has been adapted to reconstruct and explore the tectonic sources and sinks of carbon on Earth over geological timescales. This image shows a tectonic reconstruction at 55 million years ago, during the final closure of the gateway of the ancient equatorial Tethyan ocean. Colors highlight areas where carbon is exchanged between shallow and deep Earth reservoirs.

Credit: Sabin Zahirovic, University of Sydney, Australia Download at

The resilience of microbes is unmatched. DCO researchers found them surviving--sometimes thriving--in the most extreme environments. Candidatus Desulforudis audaxviator, the purplish-blue rod-shaped cells (just a few microns long), for example, lives 2.8 kilometers beneath Earth's surface at Mponeng Gold Mine near Johannesburg, South Africa. It survives on hydrogen produced by water-rock interactions. Credit: Gaetan Borgonie, ELJ, Belgium. Download at

Basalt eruptions, mammoth compared to this one in Iceland in 2014, have occurred at times through Earth's history, causing large-scale perturbations to the deep carbon cycle and mass extinctions. Credit: Robert White, University of Cambridge, UK. Download at

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