%0 Journal Article
%T Caratteristiche sedimentologico-ichnologiche delle unit¨¤ silicoclastiche oligo-mioceniche nel transetto Pratomagno¨CVerghereto, Appennino Settentrionale
%A Marco Milighetti
%A Paolo Monaco
%A Alessio Checconi
%J Museologia Scientifica e Naturalistica
%D 2009
%I Universit¨¢ Degli Studi di Ferrara
%X This study focuses on the sedimentological, stratigraphical and ichnological integrated analysis of Oligo-Miocene flysch and hemipelagic deposits outcropping in the central part of Northern Apennines (Tuscany and Emilia Romagna regions, Italy). The aim of this paper is to characterise poorly known aspects of siliciclastic deposits (ichnology) in the Pratomagno¨CVerghereto transect, in order to perform a paleoenvironmental reconstruction and to better understand and interpret the evolution of the foredeep during the Oligo-Miocene. For our purposes, over 20 sections have been studied along a transect that goes from the Tuscany (Pratomagno) to the Romagna area (Verghereto). In this region, several turbiditic formations crop out and they belong to the Cervarola¨CFalterona outer Tuscany Domain (Varicolori, Arenarie di Monte Falterona and Complesso Caotico, Arenarie di Monte Cervarola and Vicchio Formations) and to the Umbrian¨CRomagna Domain (Marnoso-arenacea e Marne di Verghereto Formations).A sedimentological characterisation of the Oligo-Miocene deposits outcropping in the studied area has been carried out in order to better define the stratigraphic and tectonic relationship of each stratigraphic unit. Four different groups of turbidites were distinguished on the base of grain size: a) very coarse grained facies due to cohesive debris (CDF) flows and hyperconcentrated flows (HCF); b) coarse-medium grained facies, originated from highdensity coarse-grained turbidity currents (GHDTC); c) medium-fine grained facies, deriving from sandy high-density turbidity currents (SHDTC); d) finegrained and/or muddy facies, due to low density flows (LDTC).Several physical sedimentary structures are present either at the base and within the turbiditic beds. The most frequent structures are represented by cross-bedded ripples, mega-ripples and microripples (mainly within muddy facies) and plane beds (generally very rich in trace fossils). At the base of the beds have been commonly recorded casts as tool casts, flute casts, chevron casts, groove casts and load casts. Skip, prod and bounce marks are also common. Clay chips, that are partially-consolidate shreds of the original substrate tore and eroded by strong currents and re-deposited basinward.Biologically induced structures are also very abundant within the analysed deposits. The taxonomic assessment of trace fossils represented an important tool in reconstructing the palaeoenvironmental evolution of flysch deposits. The abundance and the type of bioturbation are good indicators of the palaeoenvironment where the burrowers
%K Sedimentology
%K Ichnology
%K Flysch deposits
%K ichnocenoses
%K Oligo-Miocene
%K Apennines
%U http://annali.unife.it/museologia/milmonche.pdf