Serpentinization as a route to liberating phosphorus on habitable worlds

Abstract

<jats:title>Abstract</jats:title> <jats:p>Planetary habitability is in part governed by nutrient availability, including the availability of the element phosphorus. The nutrient phosphorus plays roles in various necessary biochemical functions, and its biogeochemical cycling has been proposed to be extremely slow due to a strong coupling to the rock cycle via mineral weathering. Here we show a route to P liberation from water-rock reactions that are thought to be common throughout the Solar System. We report the speciation of phosphorus in serpentinite rocks to include the ion phosphite (HPO32- with P3+) and show that reduction of phosphate to phosphite is predicted from thermodynamic models of serpentinization. As a result, as olivine in ultramafic rocks alters to serpentine minerals, phosphorus as soluble phosphite should be released under low redox conditions, liberating this key nutrient for life. Thus, this element may be accessible to developing life where water is in direct contact with ultramafic rock, providing a source of this nutrient to potentially habitable worlds.</jats:p>

Catalytic Prebiotic Formation of Glycerol Phosphate Esters and an Estimation of Their Steady State Abundance under Plausible Early Earth Conditions

“…The minerals utilized in the present work are also prebiotically relevant [37,38] while oxides of iron, such as hematite and magnetite, are also significant (with hematite being ubiquitous on the surface of Mars [39,40]). Furthermore, serpentinization reactions of olivine-and pyroxene-rich rocks with water produces magnetite [26][27][28][29] and would have existed on the Hadean Earth [27,[41][42][43][44].…”

“…These react with water to produce a rock type known as a serpentinite, and liberates molecular hydrogen [27,28]. Iron hydroxides, olivine, serpentinites and volcanic glasses are deemed to be of high prebiotic relevance [26,29] (also see Table 2 of [26]). In addition to the above-mentioned minerals, basaltic rocks were likely ubiquitous and are among the oldest known rocks [30].…”

Paleoenvironmental Study of the Late Cretaceous–Eocene Tethyan Sea Associated with Phosphorite Deposits in Jordan

“…Fe2O3, CaO, P2O5, SiO2, Al2O3, and TiO2 were plotted to understand the different parameters affecting the precipitation of phosphates. Ratios of 44 Ca/ 42 Ca and 143 Nd/ 144 Nd in carbonate fluorapatite can be an indication of the intensity of phosphogenesis and describe the long-term changes in ocean circulation and continental weathering [9]. The Nd isotopic compositions ( 143 Nd/ 144 Nd) may help to decipher rates of phosphate deposition [9].…”

“…The continent land configuration which has resulted from the convergence of the African and Eurasian plates affected the oceanographic setting by closure westward and the opening of Neo-Tethys eastward [19]. It has been postulated that serpentinization, which typically is associated with continental conversion, releases significant volumes of phosphate [44]. Three pulses of coldwater bodies coming from the eastern Neo-Tethys was proposed by Ref.…”

Waterworlds Probably Do Not Experience Magmatic Outgassing

“…Convection of high-pressure ices may ensure some mantlesurface exchange of nutrients (Choblet et al 2017;Journaux et al 2017;Kalousová et al 2018), and habitable surface temperatures can potentially be maintained for several billion years for very large water inventories (Kite & Ford 2018). Additionally, the rates of phosphorus liberation on waterworlds may, in fact, be comparable to that of the Earth (Pasek et al 2020;Syverson et al 2020). Temperature dependent carbon cycle feedbacks on waterworlds may even be better suited for maintaining habitability than on planets with subaerial continents (Hayworth & Foley 2020).…”