title: Biogenic Mn-Oxides in Subseafloor Basalts.
abstract: The deep biosphere of the subseafloor basalts is recognized as a major scientific frontier in disciplines like biology, geology, and oceanography. Recently, the presence of fungi in these environments has involved a change of view regarding diversity and ecology. Here, we describe fossilized fungal communities in vugs in subseafloor basalts from a depth of 936.65 metres below seafloor at the Detroit Seamount, Pacific Ocean. These fungal communities are closely associated with botryoidal Mn oxides composed of todorokite. Analyses of the Mn oxides by Electron Paramagnetic Resonance spectroscopy (EPR) indicate a biogenic signature. We suggest, based on mineralogical, morphological and EPR data, a biological origin of the botryoidal Mn oxides. Our results show that fungi are involved in Mn cycling at great depths in the seafloor and we introduce EPR as a means to easily identify biogenic Mn oxides in these environments.
authors.affiliation: Department of Palaeobiology and the Nordic Center for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Ivarsson
authors.affiliation: Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
authors.forename: Curt
authors.initials: C
authors.lastname: Broman
authors.affiliation: Department of Biomedical Engineering (MTÖ), County Council of Östergötland, Radiation Physics, Department of Medicine and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Gustafsson
authors.affiliation: Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
authors.forename: Nils G
authors.initials: NG
authors.lastname: Holm
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004777:Environment; D005580:Fossils; D005658:Fungi / Q000737:chemistry*; D019015:Geologic Sediments / Q000032:analysis / Q000382:microbiology*; D017895:Manganese Compounds / Q000032:analysis* / Q000737:chemistry; D009791:Oceanography; D010087:Oxides / Q000032:analysis* / Q000737:chemistry; D010140:Pacific Ocean; D017640:Silicates / Q000032:analysis* / Q000737:chemistry
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D017640:Silicates; C060346:basalt; C027424:manganese oxide