Fig. 2
Tectonic overview: (A) Main tectonic units: blue—Helvetic Nappes & Jura fold-and-thrust belt; orange—External Basement Massifs; dark blue—Sub-Penninic units (European distal continental margin); green—Penninic units comprising Alpine Tethyan units (Valais, Piemont-Liguria ophiolites) and Briançonnais (European continental margin); light brown—Austro-Alpine Nappes; dark brown—Southern Alps (Adriatic continental margin); purple—Northern Calcareous Alps (NCA); red—Tertiary Periadriatic intrusives, enclosed white area—Cenozoic basins (Molasse, Po-Veneto, Pannonian). Brown lines—cross sections numbered according to Figures in text: 4A – NFP20W; 4B—NFP20E; 5A – Entlebuch; 5B – Perwang; 6A – TRANSALP; 6B – section parallel to EASI based on seismology and interpretations, respectively, in14,15,16,17,18,19; (B) Crustal blocks during Neogene-to-recent indentation: Indenting blocks at the deformed leading edge of the Adriatic Plate: Dolomites Subindenter (red-brown), Ivrea Subindenter (yellow–brown) including the Ivrea Zone, IZ (yellow). Thick arrows indicate Neogene motion of Adria with respect to Europe. Indentation increases eastward from the counterclockwise rotation pole (yellow star) of Adria with respect to Europe. Thin black arrows indicate motion of indented orogenic blocks with respect to Europe: AlCaPa Escape Block (blue) and Northern Calcareous Alps Block, NCA (violet). Indented orogenic crust of the Central Alps comprises the Central Alps Block, kinematically connected to the Jura fold- & thrust sheet. The Jura thrust front (JF) and Northern orogenic front (NF) bound the pro-wedge of the Alpine orogen. The Southern orogenic front (SF) bounds the retro-wedge. The Western Alps and Ligurian Blocks experienced counterclockwise oroclinal bending in Early-Mid-Tertiary time. Other indentational structures: orange – External Basement Massifs including the Aar Massif (AM); bright red—Tertiary post-nappe metamorphic domes (LE—Lepontine, TW—Tauern Window). Faults: AC—Argentera-Cuneo Fault, BF—Brenner Normal Fault, EF – Engadine Fault, GB – Giudicarie Belt, GF – Giudicarie Fault, JF – Jura thrust front, KF – Katschberg Normal Fault, NF – Northern orogenic front, PF—Periadriatic Fault, PR—Penninic Front, RS—Rhône-Simplon Fault System, SEMP—Salzach–Ennstal–Mariazell–Puchberg Fault, SF – Southern orogenic front (active segment marked red), VS – Valsugana Thrust. Thin black lines—borders of peripheral basins.
