Dre Aude Picard - Role of iron sulfide mineral formation in the preservation of organic carbon

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Dre Aude Picard, U. Nevada, Las Vegas

Vendredi 1er novembre 2019 à 11h00 - Friday, November 1st, 2019 at 11:00am

Gill Room, FDA 232, 3450 rue Université, Université McGill

Résumé / abstract:

Résumé / Abstract:

The long-term burial of organic carbon and iron sulfide minerals controls oxygen and carbon dioxide concentrations at the surface of the Earth. Microbial sulfate reduction contributes to the oxidation of most organic carbon in anoxic sedimentary environments. This process is coupled to the production of sulfide, which can react with Fe(II) to precipitate iron sulfide minerals. It was long assumed that sulfate-reducing microorganisms only provide sulfide for the formation of the minerals. However, they also influence the physical properties and composition of iron sulfide minerals, by acting as templates for mineral nucleation and growth. Considering the stability and reactivity of biogenic minerals is essential to understand iron sulfide mineral formation pathways. Biogenic iron sulfide minerals also incorporate organic molecules that derive from microbial biomass. I will present the results of biomineralization experiments and discuss how iron sulfide mineral formation in the presence of sulfate-reducing microorganisms produces strong organo-mineral interactions between microbial labile organic carbon and iron sulfide minerals that have the potential to preserve OC for long periods of time.

Bio:
I am a geomicrobiologist with research interests in astrobiology and biogeochemistry. I obtained a PhD in geomicrobiology from the University in Lyon and acquired an interdisciplinary postdoctoral experience at the Max Planck Institute for Marine Microbiology (Bremen, Germany), at the University of Tubingen (Germany) and at Harvard University. I am currently Assistant Research Professor at the University of Nevada, Las Vegas. My research investigates the formation of biominerals in anoxic environments, and their role in biogeochemical cycles. I use microscopy and spectroscopy to characterize biogenic minerals produced in a variety of experimental conditions. 
 

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Role of iron sulfide mineral formation in the preservation of organic carbon

Ajouter au calendrier 2019-11-01 11:00:00 2020-02-27 19:08:57 Dre Aude Picard - Role of iron sulfide mineral formation in the preservation of organic carbon Résumé / Abstract: The long-term burial of organic carbon and iron sulfide minerals controls oxygen and carbon dioxide concentrations at the surface of the Earth. Microbial sulfate reduction contributes to the oxidation of most organic carbon in anoxic sedimentary environments. This process is coupled to the production of sulfide, which can react with Fe(II) to precipitate iron sulfide minerals. It was long assumed that sulfate-reducing microorganisms only provide sulfide for the formation of the minerals. However, they also influence the physical properties and composition of iron sulfide minerals, by acting as templates for mineral nucleation and growth. Considering the stability and reactivity of biogenic minerals is essential to understand iron sulfide mineral formation pathways. Biogenic iron sulfide minerals also incorporate organic molecules that derive from microbial biomass. I will present the results of biomineralization experiments and discuss how iron sulfide mineral formation in the presence of sulfate-reducing microorganisms produces strong organo-mineral interactions between microbial labile organic carbon and iron sulfide minerals that have the potential to preserve OC for long periods of time. Bio: I am a geomicrobiologist with research interests in astrobiology and biogeochemistry. I obtained a PhD in geomicrobiology from the University in Lyon and acquired an interdisciplinary postdoctoral experience at the Max Planck Institute for Marine Microbiology (Bremen, Germany), at the University of Tubingen (Germany) and at Harvard University. I am currently Assistant Research Professor at the University of Nevada, Las Vegas. My research investigates the formation of biominerals in anoxic environments, and their role in biogeochemical cycles. I use microscopy and spectroscopy to characterize biogenic minerals produced in a variety of experimental conditions.    Gill Room, FDA 232, 3450 rue Université, Université McGill Geotop admin@example.com America/New_York public