English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The influence of bacterial activity on phosphorite formation in the Miocene Monterey Formation, California

MPS-Authors
/persons/resource/persons210296

Brunner,  B.
Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Max Planck Society;

/persons/resource/persons210853

Wehrrnann,  L. M.
Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Berndmeyer, C., Birgel, D., Brunner, B., Wehrrnann, L. M., Joens, N., Bach, W., et al. (2012). The influence of bacterial activity on phosphorite formation in the Miocene Monterey Formation, California. Palaeogeography, Palaeoclimatology, Palaeoecology, 317, 171-181.


Cite as: http://hdl.handle.net/21.11116/0000-0001-C885-7
Abstract
Authigenic phosphorites from the Miocene Monterey Formation (California) including an autochthonous phosphatic laminite were analyzed for molecular biomarkers, element content, and sulfur isotopic composition of associated pyrite and sulfate to evaluate the role of bacterial activity in the precipitation of phosphate minerals. The phosphorites formed in a depositional environment typified by upwelling with dynamic bottom currents and hardground formation. Pyrite enclosed in the phosphorites shows δ34S values as low as − 36.5‰ VCDT, which is consistent with bacterial sulfate reduction. In a three-step extraction—phosphorite dissolution—extraction procedure, molecular fossils of sulfate-reducing bacteria (di-O-alkyl glycerol ethers and short-chain branched fatty acids i- and ai-C15:0, i- and ai-C17:0, and 10MeC16:0) were preferentially released from the mineral lattice. This suggests that the molecular fossils were tightly bound to carbonate fluorapatite, indicating that sulfate-reducing bacteria were involved in mineral formation. A close association of sulfate-reducing bacteria with large sulfide-oxidizing bacteria, which was previously suggested to favor carbonate fluorapatite precipitation, could neither be confirmed nor excluded for the Miocene Monterey Formation phosphorites.