Sedimentary filling of a wedge-top basin and relationship with the foredeep (Middle Miocene Marnoso-arenacea Formation, northern Apennines)

Abstract

The Middle Miocene Marnoso-arenacea Formation at Deruta in the northern Apennines of Italy rests unconformably on an orogenic wedge adjacent to the Adriatic foredeep. Based on a detailed facies analysis, the succession reveals two genetically related depositional systems: a distal delta-fed sand-rich system and a more proximal fan-delta slope system. Petrographic data conWrm the genetic relationship between the two depositional systems, with the fan-delta slope feeding the basinward sandrich system. The Deruta depositional setting shows a multistep sedimentary evolution controlled by tectonically induced relative sea-level changes. The Wrst stage, corresponding to a sea-level rise, promoted deposition in a wedge-top basin of pebbly sand and sand lobes (delta-fed). The second stage, characterized by intense tectonic activity (uplift) and sea-level fall, promoted accumulation of a prograding fan-delta slope replacing the sand-rich lobes. This phase was dominated by mass failures and methanogenic cold seepages. During these two stages, the wedge-top basin was isolated from the adjacent foredeep. Only during the third stage was a connection established, with the development of a deep-sea fan in the foredeep, fed by a deltaic depositional system.

Stratigraphic evolution of a submarine channel–lobe complex system in a narrow fairway within the Magallanes foreland basin, Cerro Toro Formation, southern Chile

“…However, submarine mini-basins along the margins of foreland basins are considerably less well known. Outcrop examples include several Grès d'Annot mini-basins of the French Alpine foreland basin (Sinclair, 2000;McCaffrey and Kneller, 2001;Amy et al, 2007); the Taveyannaz sandstone in the "Inner" sub-basin of the North Alpine Foreland Basin, Eastern Switzerland (Sinclair, 1992); the intra-slope mini-basin in the Tres Pasos Formation in the Magallanes foreland Basin, southern Chile (Shultz and Hubbard, 2005); the Apennine satellite basins (Ricci Lucchi, 1986, 1990, such as the Deruta wedge top basin (Conti et al, 2008) in Northern Italy; and the sub-basins in the Southern Pyrenean foreland basin, Spain (Ardèvol et al, 2000). Subsurface examples include piggyback basins of the Upper Puchkirchen Formation in the Upper Austrian Molasse Basin (Covault et al, 2009).…”

Miocene Seep-Carbonates of the Northern Apennines (Emilia to Umbria, Italy): An Overview

“…Seep-carbonates in Deruta (early phase of the closure) are included in the Marnoso-arenacea Fm at different stratigraphic levels associated with coarse-grained pebbly sandstones and conglomerates (delta-slope and large-scale mass-wasting deposits) in the wedge-top area, prograding into the inner Marnoso-arenacea foredeep. The release of abundant methane-rich fluids through thrust faults pervaded coarse-grained sediments, causing the precipitation of authigenic seep-carbonates both along the delta-slope and the adjacent foredeep (geological details in [44]).…”

The influence of intrabasinal tectonics in the stratigraphic evolution of piggyback basin fills: Towards a model from the Tremp-Graus-Ainsa Basin (South-Pyrenean Zone, Spain)

“…As an example, regional-scale piggyback basin studies usually consider only two major changes in basin fill dynamics, commonly described as (1) marine / undersupplied / transgressive stage, followed by a (2) continental / oversupplied / regressive stage that are considered to be mainly controlled by the development of regional / local syn-A C C E P T E D M A N U S C R I P T 4 depositional tectonic structures, or by the setting and erosion of new thrust sheets (Ferrière et al, 1998(Ferrière et al, , 2004Evans and Elliott, 1999;Martıń-Martıń and Martıń-Algarra, 2002; Rossi et al, 2002;Chiang et al, 2004;Conti et al, 2008;Maestro, 2008;Gugliotta, 2012;Gugliotta and Morticelli, 2012;Suriano et al, 2015). These two oversimplified stages appear in most of piggyback basin reconstructions, which are often based on detailed studies of discrete segments of the basin.…”