Apatite fission‐track analysis of Neogene exhumation in northern Corsica (France)

Abstract

Apatite fission‐track analyses along a W–E‐orientated transect across northern Corsica indicate an important episode of crustal exhumation in late early Miocene time. Samples taken from the Alpine orogenic wedge, from the adjacent foreland basin and from the crystalline basement complex flooring the basin are completely reset. This implies that a ≥ 2.0–2.3‐km‐thick crustal section made of thrust sheets and/or autochthonous foreland deposits has been removed by erosion since early Miocene time. A geometric projection of this lost cover towards the west indicates that all of northern Corsica was covered either by Alpine nappes or middle Eocene foreland deposits. Fission‐track ages are the same across the main boundary fault system separating the Alpine orogenic wedge and the foreland, indicating the absence of significant differential vertical displacement between upper and lower plates during Neogene unroofing.

Pressure–temperature–deformation–time of the ductile Alpine shearing in Corsica: From orogenic construction to collapse

“…The early Miocene ductile extension and the continuous transition to brittle extensional faulting documented in this study reinforce the significance of the early Miocene rapid exhumation event already detected in the Alpine Corsica region (Cavazza et al, 2001;Fellin et al, 2005;Zarki-Jakni et al, 2004). In this view, conclusive evidence is provided to assert that deposition of the early Miocene (Burdigalian-Langhian) Saint Florent basin (Cavazza et al, 2007;Ferrandini et al, 1998) on top of the exhuming HP units (Fig.…”

“…Zircon and apatite fission-track thermochronology attests for a continuous cooling of the Hercynian and Schistes Lustrés units between late Eocene and Miocene times (between c. 40 and 15 Ma; Cavazza et al, 2001;Fellin et al, 2006;Zarki-Jakni et al, 2004). In particular, fission track ages and the U-Th/He data on apatite indicate a major cooling/ exhumation event starting in the early Miocene (at~20 Ma), commonly related to back-arc extension during the Liguro Provençal and Tyrrhenian rifting (Cavazza et al, 2001;Fellin et al, 2005Fellin et al, , 2006Zarki-Jakni et al, 2004).…”

Survival of Ancient Landforms in a Collisional Setting as Revealed by Combined Fission Track and (U-Th)/He Thermochronometry: A Case Study from Corsica (France)

“…AFT data show that Variscan Corsica experienced cooling below ∼100ЊC during the Early Oligocene to Middle Miocene. This cooling is interpreted to have been related to erosional and tectonic denudation of the basement from below the Alpine nappes and foreland sediments (Cavazza et al 2001;Danišík et al 2007).…”

“…A great deal of AFT and ZFT data have been reported from Corsica (Carpé na et al 1979;Lucazeau and Mailhé 1986;Mailhé et al 1986;Jakni et al 2000;Cavazza et al 2001;Zarki-Jakni et al 2004;Fellin et al 2005aFellin et al , 2006Danišík et al 2007). More recently, zircon and apatite (U-Th)/He data from Alpine Corsica were reported (Fellin et al 2005b).…”

Erosion rates on subalpine paleosurfaces in the western Mediterranean by in-situ 10Be concentrations in granites: implications for surface processes and long-term landscape evolution in Corsica (France)

“…Major sinistral faulting and tilting occurred during Early Miocene differential counter-clockwise rotation (Gorini et al 1993). The Alpine wedge on the eastern side of Corsica experienced Late Oligocene to Middle Miocene extension (Brunet et al 2000;Cavazza et al 2001), which turned to uplift in the Late Miocene (Orszag-Sperber and Pilot 1976;Ferrandini et al 1998).…”