Hydrothermal Production of Organic molecules: carbon transformation and Decomposition in ocean crust fluids

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2019

End date

12/31/2023

Budget

1,253,862 EUR

Fundings

Abstract

The global mid-ocean ridge is dotted with deep-sea hot springs fueling a 'deep biosphere' of ancient microorganisms, likely the first to emerge on Earth. The ocean is thus considered the 'cradle of life', yet the nexus of this thinking - the potential for dissolved organic molecules to spontaneously form in these hot spring fluids - is a process we do not fully understand. Emerging evidence of diverse organic molecules in hot, reducing fluids emanating from these aquifers suggests they form by multiple pathways, including non-biological CO2 reduction (generating abiotic molecules from which life can emerge), and thermal breakdown of crustal microbial carbon or dissolved organic matter (DOM) - perhaps signifying life's presence beneath the seafloor. Both abiotic synthesis of origin-of-life relevant molecules, and pyrolysis of pre-existing organic matter are poorly studied phenomena at conditions of deep-sea hot springs, leaving huge gaps in our understanding of carbon transformation in ocean crust fluids. Understanding hydrothermal production of the small organic molecules now detectable is critical for assessing energy sources for biotech-relevant microbes, and a potential hydrothermal origin of life on Earth and other ocean worlds in our Solar System (e.g. Enceladus). HyPOD is currently examining generation of diverse hydrocarbons, sulfur-, nitrogen- and oxygen-rich organic molecules from multiple carbon sources (CO2 reduction, as well as microbial carbon, DOM, sedimentary kerogen pyrolysis) in hot springs, using state-of-the-art high temperature-pressure experiments and theoretical models to illuminate the diversity, differences & isotope signatures of organic products formed. The HyPOD team has already analyzed a large portfolio of seafloor hydrothermal fluids sampled either before or during the project from diverse Arctic, Mid-Atlantic and Caribbean mid-ocean ridge hydrothermal systems. We have measured both carboxylic acids as well as methanol - a key origin-of-life relevant compound - in our organic analyses of real hot spring fluids, results that will be critical for our understanding of carbon cycling in volcanic ocean crust. We are now undertaking experiments to reveal the high-temperature fate of microbial deep biosphere and sedimentary carbon, and the formation of prebiotic hydrothermal organic ingredients for the origin of life.