The Anisian–Carnian Verrucano Group of the Tuscan Metamorphic Units and the Triassic–Hettangian Pseudoverrucano Formation of the homonymous unit are mainly continental redbeds occurring in Tuscany at the base of the Alpine orogenic cycle. A study carried out throughout the Apennine, Maghrebian and Betic Chains emphasized the presence in all these orogenic belts of deposits more or less coeval and similar both to the metamorphic Verrucano and to the unmetamorphosed Pseudoverrucano. Thus, the distinction of Verrucano and Pseudoverrucano successions has a palaeogeographical and geodynamic importance at the scale of the Western Mediterranean. Both successions developed during the continental rift stage of Pangaea, which led to later break-up at the edges of a future microplate, interposed between the Europe, Africa and Adria–Apulia plates, but they are characterized by different tectono-metamorphic evolution. Pseudoverrucano-like deposits, devoid of Alpine metamorphism, characterize the highest tectonic units of the nappe stack and they overthrust units bearing Verrucano-like deposits. These latter show an Alpine tectono-metamorphic history marked during the Miocene by intense deformation and HP/LT metamorphism (at pressures in the range of 0.8–2 GPa), followed by a retrograde phase associated with decompression, suggesting subduction and subsequent exhumation of continental crust. Intriguing palaeogeographical problems arise from the analysis of Verrucano-bearing units, because the same evolution seems to characterize both units considered to belong to a realm similar to that of the north-verging Austroalpine nappe system and some units referred to the south-verging fold–thrust belt derived from the Adria–Apulia palaeomargin.

“Verrucano” and “Pseudoverrucano” in the central-western Mediterranean Alpine chains: palaegeographical evolution and geodynamic significance.

PERRONE, VINCENZO;
2006

Abstract

The Anisian–Carnian Verrucano Group of the Tuscan Metamorphic Units and the Triassic–Hettangian Pseudoverrucano Formation of the homonymous unit are mainly continental redbeds occurring in Tuscany at the base of the Alpine orogenic cycle. A study carried out throughout the Apennine, Maghrebian and Betic Chains emphasized the presence in all these orogenic belts of deposits more or less coeval and similar both to the metamorphic Verrucano and to the unmetamorphosed Pseudoverrucano. Thus, the distinction of Verrucano and Pseudoverrucano successions has a palaeogeographical and geodynamic importance at the scale of the Western Mediterranean. Both successions developed during the continental rift stage of Pangaea, which led to later break-up at the edges of a future microplate, interposed between the Europe, Africa and Adria–Apulia plates, but they are characterized by different tectono-metamorphic evolution. Pseudoverrucano-like deposits, devoid of Alpine metamorphism, characterize the highest tectonic units of the nappe stack and they overthrust units bearing Verrucano-like deposits. These latter show an Alpine tectono-metamorphic history marked during the Miocene by intense deformation and HP/LT metamorphism (at pressures in the range of 0.8–2 GPa), followed by a retrograde phase associated with decompression, suggesting subduction and subsequent exhumation of continental crust. Intriguing palaeogeographical problems arise from the analysis of Verrucano-bearing units, because the same evolution seems to characterize both units considered to belong to a realm similar to that of the north-verging Austroalpine nappe system and some units referred to the south-verging fold–thrust belt derived from the Adria–Apulia palaeomargin.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11576/1889761
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact