caa a22 4500 467934142 CHVBK 20180406152952.0 cr unu---uuuuu 170328e20060501xx s 000 0 eng 10.1007/s10347-005-0032-2 doi (NATIONALLICENCE)springer-10.1007/s10347-005-0032-2 Petrography and biosedimentology of the Rosso Ammonitico Veronese (middle-upper Jurassic, north-eastern Italy) [Elektronische Daten] [Alain Préat, Salvatore Morano, Jean-Paul Loreau, Christophe Durlet, Bernard Mamet] A petrographic and biosedimentological study of the Rosso Ammonitico Veronese from the Trento Plateau (north-eastern Italy) shows that diagenetic (neomorphism, recrystallization) and biological processes (microbial content and pigmentation) influenced the formation and alteration of the carbonate matrix. The subject of this article is the interaction of early diagenetic processes and an attempt to explain the different colors of the matrix (red, pink, grey). Nearly 200 samples derived from 14 sections (Callovian to Tithonian) located in the Verona area have been studied by means of classical, cathodoluminescence and SEM microscopy. Calcite and ferruginous microfilaments of different shapes and sizes are present and tentatively attributed to fungi and iron bacteria. These micro-organisms precipitated iron oxy-hydroxides at poorly dysoxic-anoxic sediment-water interfaces. Further liberation of submicronic hydroxides (now hematite) was responsible for the red pigmentation of the carbonate matrices, originally composed of less than 1 μm-sized micrite. Controversial smaller nanograins (0.1-0.5μm) attributed to nanobacteria or planktonic picoeukaryotes have been observed in the reddish samples. Recrystallization of the micrite leads to the formation of new micritic crystals, between 2 and 4μm in size, then to microspar crystals. Micritic textures are linked to the different colours of the samples. The intensity of the red colour is correlated with the presence of hematite (former iron hydroxides) and the presence of planar subhedral micritic grains. In contrast, pink and greyish samples are linked to the increasingly coalescent structure of anhedral micritic and microsparitic crystals. Springer-Verlag, 2005 Rosso ammonitico nationallicence Bioprecipitation nationallicence Pigmentation nationallicence Diagenesis nationallicence Micrite nationallicence Jurassic nationallicence Préat Alain Département des Sciences de la Terre et de l'Environnement-Université Libre de Bruxelles. 50, avenue F. D. Roosevelt, CP, 160/02. 1050, Brussels, Belgium aut Morano Salvatore Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut Loreau Jean-Paul Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut Durlet Christophe Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut Mamet Bernard Département des Sciences de la Terre et de l'Environnement-Université Libre de Bruxelles. 50, avenue F. D. Roosevelt, CP, 160/02. 1050, Brussels, Belgium aut Facies Springer-Verlag 52/2(2006-05-01), 265-278 0172-9179 52:2<265 2006 52 10347 https://doi.org/10.1007/s10347-005-0032-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10347-005-0032-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Préat Alain Département des Sciences de la Terre et de l'Environnement-Université Libre de Bruxelles. 50, avenue F. D. Roosevelt, CP, 160/02. 1050, Brussels, Belgium aut NATIONALLICENCE 700 1- Morano Salvatore Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut NATIONALLICENCE 700 1- Loreau Jean-Paul Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut NATIONALLICENCE 700 1- Durlet Christophe Centre des Sciences de la Terre, UMR CNRS 5561, 6 Bd Gabriel, 21000, Dijon, France aut NATIONALLICENCE 700 1- Mamet Bernard Département des Sciences de la Terre et de l'Environnement-Université Libre de Bruxelles. 50, avenue F. D. Roosevelt, CP, 160/02. 1050, Brussels, Belgium aut NATIONALLICENCE 773 0- Facies Springer-Verlag 52/2(2006-05-01), 265-278 0172-9179 52:2<265 2006 52 10347 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer