Volcanism and Volcanogenic Submarine Sedimentation in the Paleogene Foreland Basins of the Alps: Reassessing the Source-to-Sink Systems with an Actualist View

Abstract

This work critically reviews the Eocene–Oligocene source-to-sink systems accumulating volcanogenic sequences in the basins around the Alps. Through the years, these volcanogenic sequences have been correlated to the plutonic bodies along the Periadriatic Fault System, the main tectonic lineament running from West to East within the axis of the belt. Starting from the large amounts of data present in literature, for the first time we present an integrated 4D model on the evolution of the sediment pathways that once connected the magmatic sources to the basins. The magmatic systems started to develop during the Eocene in the Alps, supplying detritus to the Adriatic Foredeep. The progradation of volcanogenic sequences in the Northern Alpine Foreland Basin is subsequent and probably was favoured by the migration of the magmatic systems to the North and to the West. At around 30 Ma, the Northern Apennine Foredeep also was fed by large volcanogenic inputs, but the palinspastic reconstruction of the Adriatic Foredeep, together with stratigraphic and petrographic data, allows us to safely exclude the Alps as volcanogenic sources. Beyond the regional case, this review underlines the importance of a solid stratigraphic approach in the reconstruction of the source-to-sink system evolution of any basin.

Middle Eocene in the Alpine Retroforeland Basin (Northern Italy): Sedimentary Record of a “Meso-Alpine” Arc-Trench System in the Alps

“…(Di Giulio et al 2005; Fig. 9) has revealed a calcic composition (labradorite/bytownite: An 55-85 ), recently confirmed also by analyses on different samples from the same localities (Di Capua et al 2021a).…”

“…Relationships between the sediment sources and sinks for these units have been discussed in detail by Lu et al (2019) and Di Capua et al (2021a) and go far beyond the scope of the present paper. However, geochemical signatures of single diagnostic minerals support detailed provenance analyses documenting the prevailing influence of the Biella Pluton and the Bergell Tonalite as source rocks for the Helvetic basins during the Oligocene (Lu et al 2019), while a "southwestern" (Ligurian-Provençale) origin for the Val d'Aveto-Petrignacola clastics is indicated (Di Capua et al 2021a).…”

Deep-Water Accumulation of Volcaniclastic Detritus from a Petrographic Point of View: Beginning a Discussion from the Alpine Peripheral Basins

“…During the Paleogene, large amounts of volcaniclastic detritus were delivered to the Alpine peripheral basins, as recently reviewed by [18] (Figure 2). However, the paucity of preserved volcanic sequences and edifices, together with the accretion of the same Alpine and Apennines' belts, makes impossible the reconstruction of any Paleogene source-tosink systems or the correct interpretation of such volcaniclastic layers.…”

“…Figure 1. Regional Geological Maps of the Alps and Northern Apennines modified from [18]. The Formations object of this review are circled by red ovals.…”

Tectono-Sedimentary Evolution of Cenozoic Basins

“…Di Capua et al (2020) [6] treated the volcanism and volcanogenic submarine sedimentation in the Paleogene Foreland Basins of the Alps. In this paper, source-to-sink systems were reassessed with an actualist view.…”