- Cole, David Prof.
The overarching goal of this Deep Energy Community project is to quantify the environmental conditions and processes—from the molecular to the global scale—that control the volumes, rates of generation and reactivity of organic compounds derived from deep carbon through geologic time. The primary objective is to develop a transformative research program designed to answer the key grand challenge questions pertaining to the generation, flux, and reactivity of abiotic carbon compounds in crustal and uppermost mantle settings. The project addresses how to differentiate between abiotic versus biotic carbon, define the nature of the biotic to abiotic transition in the crust, assess the role of H2-generating reactions such as serpentinization in controlling this transition, determine the reaction mechanisms and rates that control the formation and reactivity of hydrogen and organic compounds, identify the forms of reduced carbon in the crust and upper mantle, and explore the global distribution, budget, mobility and fluxes of abiotic carbon/H2 and their impact of the global carbon cycle.
The international “community-building” team of 21 researchers (17 institutions) from 8 countries is leveraging state-of-the-art sampling and new DCO-funded analytical methods to characterize unique sample suites obtained from selected representative geologic settings. This combination is optimizing our chances for chemical and isotopic “finger-printing” of the signatures of abiotic versus biogenic carbon-bearing compounds. Novel experimental and modeling methods are being used to probe the macroscopic to molecular-level consequences of processes controlling water-rock interactions between key candidate deep-Earth mineral substrates like olivine, and aqueous fluids that transform into serpentine and produce H2, CH4 and higher hydrocarbons over a large range of temperature (40-350°C) and pressure (0.1-300 MPa).
Team members have started publishing high-profile peer-reviewed publications based on their findings. We expect this project to produce an expanded global network of 10 key geologically representative field sites, and among them, 2 sites suitable for detailed time-series testing of biotic versus abiotic sources. Standards for sampling acquisition, preservation, sharing and analytical protocols should become available to the larger community by the end of this project as well as isotopologue benchmarks for methane end-members from biotic and abiotic experimental sources. Outcomes include new instruments for the analysis of isotopologues, global databases of noble gas and hydrocarbon inventories that will certainly help determine the likelihood of the end-member isotopologues series leading to the selection of the representative geologically field sites. In the process, heretofore-separate communities of experimentalists, theoreticians and field geologists will become integrated. We intend that this Deep Energy project will stimulate integrated efforts from the entire DCO community for sourcing subsurface reduced carbon in the widespread context of water-rock context where Deep Life may interplay. As an example a Deep Energy-Deep Life joint meeting was held in Lyon in April of 2014 to explore projects of mutual interest.