The Late Oligocene to Early Miocene foredeep basin system evolution of the Northern Apennines (Emilia-Tuscany, Italy): review and new litho- and biostratigraphic data

Gianluca Cornamusini (1,2), Paolo Conti (1,2) & Anna Maria Bambini (1)
(1) Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy. (2) Center for Geotechnologies, University of Siena, San Giovanni Valdarno (AR), Italy. Corresponding author e-mail: cornamusini@unisi.it.

The Oligocene-Miocene turbidite successions of the Emilia-Tuscany Apennines are one of the most intriguing aspects of the geology of the Northern Apennines (NA) in Italy. To better understand the stratigraphic and tectonic evolution of this sector of the NA, we conducted a detailed field-mapping and stratigraphic study of turbidite successions of the most critical areas of this sector of the chain, which are composed of Mt. Modino Sandstone, Mt. Cervarola Sandstone, Gova Sandstone and associated marly units. Our contribution encompasses a review of the regional geology and fieldrelationships of arenaceous and marly formations, with a particular focus on new biostratigraphic data. This new biostratigraphic study is coupled with a compositional characterization of sandstone, with a view to producing a paleogeographic and evolutionary model of the thrust-foredeep system of the NA during the late Oligocene-early Miocene. This system was structured in a first stage during the Chattian-Aquitanian with the development of different inner turbidite systems (the Mt. Modino Sandstone in the frontal thrust-top basin, the Macigno, the Torre degli Amorotti System of the Mt. Cervarola Sandstone and the Gova Sandstone in the foredeep). The orogenic wedge was then affected by a later important deformation event during the earliest Burdigalian (Tuscan phase), developing the wider foredeep of the Mt. Cervarola Sandstone basin.

nannofossil biostratigraphy, turbidite system, foredeep basin, Oligocene-Miocene, Northern Apennines.