Oceanic Pillow Lavas and Hyaloclastites as Habitats for Microbial Life Through Time – A Review

Abstract

This chapter summarizes research undertaken over the past 15 years upon the microbial alteration of originally glassy basaltic rocks from submarine environments. We report textural, chemical and isotopic results from the youngest to the oldest in-situ oceanic crust and compare these to data obtained from ophiolite and greenstone belts dating back to c. 3.8 Ga. Petrographic descriptions of the granular and tubular microbial alteration textures found in (meta)-volcanic glasses from pillow lavas and volcanic breccias are provided and contrasted with textures produced by abiotic alteration (palagonitization). The geological setting in particular the degree of deformation and metamorphism experienced by each study site is documented in outcrop photographs, geological maps and stratigraphic columns (where possible). In addition, X-ray mapping evidence and carbon isotopic data that are consistent with a biogenic origin for these alteration textures is explained and a model for their formation is presented. Lastly, the petrographic observations and direct radiometric dating techniques that have been used to establish the antiquity and syngenicity of these microbial alteration textures are reviewed.

Fungal colonies in open fractures of subseafloor basalt

“…Furnes et al 2008;Staudigel et al 2008;McLoughlin et al 2009) or as body fossils in veins and vesicles filled by secondary carbonates (Schumann et al 2004;Ivarsson and Holm 2008;Ivarsson et al 2008aIvarsson et al , 2008bPeckmann et al 2008;Eickmann et al 2009;Cavalazzi et al 2011). Ivarsson et al (2008aIvarsson et al ( , 2008b described filamentous fossilized microorganisms from the Emperor Seamounts in the Pacific Ocean in carbonate-filled veins and vesicles to a depth of~900 metres below seafloor (mbsf).…”

Ideas and perspectives: Hydrothermally driven redistribution and sequestration of early Archaean biomass – the hydrothermal pump hypothesis

“…Prokaryotic primary producers and heterotrophs may have flourished in microbial mats (Dresser stromatolites; Walter et al, 1980;Van Kranendonk, 2006, 2011Philippot et al, 2007;Van Kranendonk et al, 2008), the water column (planktic 'marine snow', Brasier et al, 2006;Blake et al, 2010), and hotsprings on land (Djokic et al, 2017). Another biological source for the ancient organic matter could have been chemoautotrophs and heterotrophs thriving in more cryptic environments such as basalts (Banerjee et al, 2007;Furnes et al, 2008) and hydrothermal vent systems (Shen et al, 2001;Ueno et al, 2001Ueno et al, , 2004Ueno et al, , 2006Pinti et al, 2009;Morag et al, 5 2016) (Fig. 4).…”

Subseafloor basalts as fungal habitats

“…Subseafloor basalts are today established as microbial habitats (e.g. Thorseth et al, 2001;Furnes et al, 2008;Orcutt et al 2010;Mason et al, 2010), and biogenicity of filamentous fossilized microorganisms interpreted as fungal hyphae has been reported from these exact samples (Ivarsson et al, 2008a(Ivarsson et al, , b, 2009(Ivarsson et al, , 2012. Thus, the geologic context is compatible with microbial life.…”

“…It is a Fe, Si, Al, C-mix with minor amounts of Ca, Mg, Ti, Mn. The detection of P in the smaller bodylike structures is also interesting since P is a relevant element in biology and sometimes used as an indication of biological remnants in fossilized material (Giovannoni et al, 1996;Furnes and Muehlenbachs, 2003). It is also interesting since phosphate was detected by ToF-SIMS in the filamentous microfossils in samples from the Emperor Seamounts (Ivarsson et al, 2008a).…”