Tracking Adria indentation beneath the Alps by detrital zircon U-Pb geochronology: Implications for the Oligocene–Miocene dynamics of the Adriatic microplate

Detrital zircon U‐Pb ages and Hf isotopic constraints on the terrigenous sediments of the Western Alps and their paleogeographic implications

“…Following this shift, sediment supply increased considerably in overfilled basins in the North Alps, hinting a high relief in the Internal Zone [ Schlunegger et al ., ; Sinclair , ; Ford et al ., ]. In Oligocene‐Miocene formations, age peaks at 40–30 Ma document the exposure of rocks related to the Paleogene Alpine orogen in the Internal Zone [ Malusà et al ., ]. In the western part of the Paleogene Piedmont Basin, high Si white micas of Eocene‐Oligocene ages are discovered in the early Oligocene sediments, confirming the exhumation of Alpine high‐pressure metamorphic rocks [ Carrapa et al ., , ].…”

Continuity of the Alpine slab unraveled by high‐resolution P wave tomography

“…Noteworthy, the amount of subducted lithosphere as seen in tomography cross sections (Figure ) is fully consistent with the amount predicted by paleomagnetic and geological constraints [ Handy et al ., ; Malusà et al ., ]. About 450 km subduction took place along the central Alps trench on a geological ground [ Malusà et al ., ], and this is also the amount that can be inferred from the length of the high‐velocity anomalies (1 in Figure ). Moreover, the alpine volcanism in the Western Alps cannot be explained, to the south of the Cretaceous wedge, by slab break off of the European slab at 35 Ma, as it affects the proside foreland basin and not the upper plate (Adriatic) side of the orogen.…”

“…The steepness and downdip continuity of the Alpine slab, and its possible interaction with the Apenninic slab to the south [e.g., Vignaroli et al ., ; Malusà et al ., ], have major implications for (U)HP metamorphism, magmatism, and relief development in the Alpine region during the Cenozoic [ von Blanckenburg and Davies , ; Guillot et al ., ; Lustrino et al ., ; Faccenna et al ., ; Fox et al ., ]. However, uncertainty in both Alpine and Apenninic slab structures leaves many questions widely open, both concerning the peculiar Cenozoic magmatism in the Alps, which is classically ascribed to slab break off [e.g., von Blanckenburg and Davies , ; Dal Piaz et al ., ], and the very low paleogeothermal gradients documented during Alpine subduction, but unexpected in areas characterized by very slow convergence [ Malusà et al ., ].…”

Detrital zircon age patterns from turbidites of the Balagne and Piedmont nappes of Alpine Corsica (France): Evidence for an European margin source

“…The in situ Hf-isotope analysis of single zircon grain has proven to be a useful tool for reconstructing the tectonic evolution of continental blocks (Griffin et al, 2000;Condie et al, 2009). As a syntectonic sedimentary formation, resulting of erosion, transportation and deposition in active tectonic settings, turbidite records much information even it may lose some information due to late stage omission in orogenic belt ( Gehrels, 2014;Malusà et al, 2011Malusà et al, , 2016a.…”

“…Thus, an integration of the different analytical datasets applied to detrital zircons in sedimentary basins offers the possibility to assess the tectonic evolution history of the orogen from which the sediments were derived in terms of ages, rock types and source materials (Wysoczanski et al, 1997;Carter and Moss, 1999;Bruguier et al, 1997;Cawood et al, 2012). Detrital zircon age patterns and Lu-Hf isotopic analysis were recently used to unravel the origin of terrigenous sediments and the growth of the crusts in the Western Alps in a situation close to Alpine Corsica environment (Bütler et al, 2011;Beltrán-Triviño et al, 2013;Malusà et al, 2013Malusà et al, , 2016aManzotti et al, 2015Manzotti et al, , 2016Chu et al, 2016 and references therein; Anfinson et al, 2016).…”