Picard, A; Gartman, A; Cosmidis, J; Obst, M; Vidoudez, C; Clarke, DR; Girguis, PR: Authigenic metastable iron sulfide minerals preserve microbial organic carbon in anoxic environments, Chemical Geology (2019)
Abstract:
The burial of organic carbon (OC) in sedimentary environments promotes long-term carbon sequestration and allows the release of oxygen in the atmosphere. OC preservation in sedimentary environments is commonly enhanced during transport and deposition on the seabed through the association with terrigenous minerals that can serve as physical protectants. Here, we propose an authigenic mechanism for the coupled preservation of labile OC and metastable iron sulfide minerals under anoxic conditions. Sulfate-reducing microorganisms (SRM) are ubiquitous in anoxic environments and produce the majority of free sulfide in marine sediments, leading to the formation of iron sulfide minerals in situ. Using high spatial resolution microscopy, spectroscopy and spectro-microscopy, we show that iron sulfide biominerals precipitated in the presence of SRM incorporate and adsorb organic molecules, leading to the formation of stable organo-mineral aggregates that could persist for years in anoxic environments. OC/iron sulfide assemblages consist of the metastable iron sulfide mineral phases mackinawite and/or greigite, along with labile organic compounds derived from new microbial biomass or from extracellular organic molecules released by SRM. Together these results underscore the role that a major group of anoxic microbes play in OC preservation and illustrate the value of the resulting authigenic metastable iron sulfide minerals mackinawite and greigite in protecting labile organic molecules from degradation over time.
Aktuelle Termine


BayCEER-Kolloquium:
Do. 12.12.2019
Iron, sulfur and a pinch of antimony - new perspectives on secondary mineral pathways and metalloid mobility
Geographisches Kolloquium:
Di. 10.12.2019
Intensify or diversify? How agriculture affects biodiversity and ecosystem processes in European farmland
Di. 17.12.2019
The meat of the Anthropocene: Food, capital and the globalisation of industrialised animal killing
Ökologisch-Botanischer Garten:
So. 05.01.2020
Auf ins Neue! Winterspaziergang im ÖBG
So. 05.01.2020
Konzert: Musikalischer Jahresbeginn mit den Rockin`Dinos
BayCEER Blog
24.05.2019
Stoichiometric controls of C and N cycling
07.05.2019
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
07.05.2019
EGU – interesting research and free coffee
16.04.2019
Picky carnivorous plants?
RSS Blog als RSS Feed
Wetter Versuchsflächen
Luftdruck (356m): 969.5 hPa
Lufttemperatur: 6.8 °C
Niederschlag: 0.2 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 12.8 km/h
Wind (Max.): 27.0 km/h
Windrichtung: SW

...mehr
Globalstrahlung: 1 W/m²
Lufttemperatur: 3.1 °C
Niederschlag: 0.7 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 23.0 km/h

...mehr
Diese Webseite verwendet Cookies. weitere Informationen