Microbial endolithic colonization and the geochemical environment in young seafloor basalts

DOI: 10.1016/j.chemgeo.2010.09.015

Authors: Charles S. Cockell (Open University) , Peter Van Calsteren (Open University) , Fred W. Mosselmans (Diamond Light Source) , Ian Franchi (Open University) , Iain Gilmour (Open University) , Laura Kelly (Open University) , Karen Olsson (Open University) , Diane Johnson (Open University) , Jc24 Shipboard Scientific Party
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Geology

State: Published (Approved)
Published: October 2010

Abstract: The colonization and weathering of young seafloor basaltic glass from the mid-Atlantic Ridge was examined. Microorganisms were localised to fractures in the surface of the basalt and grew on the surfaces of material in the fractures. XAS, Raman Spectroscopy and NanoSIMS analysis of the fracture-filling material shows that it contains non-crystallised iron-enriched altered glass and poorly ordered iron oxides. Organisms, which in places develop into contiguous biofilms, develop on the surface of the material. No putative biogenic alteration textures were observed in the basaltic glass at the fracture boundaries suggesting that the microbial community is restricted to the secondary alteration products. Microbial culturing shows the presence of heterotrophic bacteria including Sufitobacter and Halomonas consistent with observations of photic zone detritus associated with fracture-filling material. These data show that the interior of fresh basaltic glass is an endolithic habitat for microorganisms, but that the glass itself is not a primary source of cations or energy for the developing communities.

Journal Keywords: Basaltic Glass; Endoliths; Palagonite; Mid-Atlantic Rift; Bacteria

Subject Areas: Environment, Chemistry


Instruments: I18-Microfocus Spectroscopy