Messinian bottom-grown selenitic gypsum

Autor(en)
Marcello Natalicchio, Daniel Birgel, Francesco Dela Pierre, Simone Ziegenbalg, Lars Hoffmann-Sell, Susanne Gier, Joern Peckmann
Abstrakt

Primary gypsum deposits, which accumulated in the Mediterranean Basin during the so-called Messinian salinity crisis (5.97-5.33 Ma), represent an excellent archive of microbial life. We investigated the molecular fossil inventory and the corresponding compound-specific delta C-13 values of bottom-grown gypsum formed during the first stage of the crisis in four marginal basins across the Mediterranean (Nijar, Spain; Vena del Gesso, Italy; Heraklion, Crete; and Psematismenos, Cyprus). All studied gypsum samples contain intricate networks of filamentous microfossils, whose phylogenetic affiliation has been debated for a long time. Petrographic analysis, molecular fossil inventories (hydrocarbons, alcohols, and carboxylic acids), and carbon stable isotope patterns suggest that the mazes of filamentous fossils represent benthic microbial assemblages dominated by chemotrophic sulfide-oxidizing bacteria; in some of the samples, the body fossils are accompanied by lipids produced by sulfate-reducing bacteria. Abundant isoprenoid alcohols including diphytanyl glycerol diethers (DGDs) and glycerol dibiphytanyl glycerol tetraethers (GDGTs), typified by highly variable carbon stable isotope composition with delta C-13 values spanning from -40 to -14 parts per thousand, reveal the presence of planktic and benthic archaeal communities dwelling in Messinian paleoenvironments. The compound inventory of archaeal lipids indicates the existence of a stratified water column, with a normal marine to diluted upper water column and more saline deeper waters. This study documents the lipid biomarker inventory of microbial life preserved in ancient gypsum deposits, helping to reconstruct the widely debated conditions under which Messinian gypsum formed.

Organisation(en)
Institut für Geologie
Externe Organisation(en)
Università degli Studi di Torino, Universität Hamburg, IFG Ingenieurbüro für Geotechnik, Institut Dr Nowak GmbH & Co KG, Universität für Bodenkultur Wien
Journal
Geobiology
Anzahl der Seiten
19
ISSN
1472-4677
DOI
https://doi.org/10.1111/gbi.12464
Publikationsdatum
07-2021
Peer-reviewed
Ja
ÖFOS 2012
105121 Sedimentologie
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/messinian-bottomgrown-selenitic-gypsum(5bc7195b-a3dd-416c-90e9-a0147dd08f24).html