Periodic Reporting for period 1 - DeepSeep (Deep Serpentinization, H2, and high-pressure abiotic CH4)
Période du rapport: 2021-06-01 au 2022-11-30
DeepSeep aims at identifying the processes, chemical features, and fluxes of dihydrogen and methane produced through the process of serpentinization in the deep Earth today and in deep time, and how these fluids may have contributed to deep subsurface biosphere processes on Earth and potentially beyond.
WP1: Three key field campaigns were done in Corsica and Vermont. Minor field activities were also done. Owing to COVID restrictions, some major field campaigns are postponed to 2023. The field work done so far has provided geological constraints and samples for laboratory analyses. More than 500 kilograms fo rocks have been collected so far for laboratory analyses. Additional samples have been obtained from international collaborators. The collected field data have allowed identifying a number of CH4 production and migration sites.
WP2: Sample characterization and the setup of the DeepSeep laboratory have been the main and most time-consuming activities during the first reporting period. The team has characterized more than 150 samples at the microscale (purchased optical and electron microscopes). Fluid inclusion characterization has already provided a large dataset on more than 80 samples from different localities. The presence of CH4 and H2 is confirmed in most of them. The setup of instrumentation and analytical protocols for fluid extraction and analysis were successfully concluded in November 2022. We plan substantial data collection for 2023.
WP3: Great step forward have been done on the compilation of the proposed numerical code for simultaneous thermodynamic and carbon isotope calculations (ThermotopesC_DEW). We also established a new collaboration aimed at establishing isotope fractionation factors for the main carbon-bearing fluid species at high-pressure conditions. These data will be integrate in the software to improve the internal consistency of the code.
Dissemination: the dissemination of DeepSeep results has started and already includes 5 papers published in international journals, including two papers in Nature Communications. Two manuscripts are currently under review. Five other manuscripts are in preparation. Two abstracts have been presented at international conferences during the first reporting period.