The western end of the Eoalpine High‐Pressure Belt (Texel unit, South Tyrol / Italy)

Abstract

Eclogites in the Texel Unit (Eastern Alps; South Tyrol, Italy) represent the westernmost outcrops of the E-W striking Eoalpine High-Pressure Belt (EHB). East of the Tauern Window, the EHB forms part of a Cretaceous intracontinental south-dipping subduction/collision zone; however, the same nappe stack displays a northwest dip at its western end. This prominent change in dip direction gave rise to discussions on the general setting of the Eoalpine collision. Based on our own observations and literature data, we present a new tectonic model for the western end of the EHB. Due to the special situation of this area at the tip of the Southalpine indenter, originally south(east) dipping structures became overturned, and former thrusts appear as normal faults (e.g. Schneeberg fault zone) while former normal faults presently display thrust geometries (e.g. Jaufen fault). Thus, we explain the current configuration with a coherent Eoalpine subduction direction.

Active Seismotectonic Deformation in Front of the Dolomites Indenter, Eastern Alps

“…1029 data are already available for the Swiss part and adjacent regions (see Kastrup et al, 2004;Marschall et al, 2013, and references therein). For the Austrian and Italian sectors, focal mechanisms are available only for some stronger events (e.g., Pondrelli et al, 2004;Slejko et al, 1987) and for earthquakes near the BF Brandner (1980b) and Bousquet et al (2012), with supplementary information from Decker et al (1994), Eisbacher and Brandner (1995), Ortner et al (2015), Pomella et al (2016), and published geologic and tectonic maps (Autonome Provinz Bozen, 2017;Bigi et al, 1990;Bundesamt für Landestopografie, 2005;Geologische Bundesanstalt, 2017a, 2017b. The Dolomites indenter (DI, the boundary is shown with a thick black line) is the South Alpine segment bounded by the Giudicarie Fault (GF) and the Pustertal-Gailtal Fault (PGF Müller (1981).…”

“…Tectonic map of the central Eastern Alps, showing important brittle faults active during late Alpine orogeny. Simplified from Brandner (1980b) and Bousquet et al (2012), with supplementary information from Decker et al (1994), Eisbacher and Brandner (1995), Ortner et al (2015), Pomella et al (2016), and published geologic and tectonic maps (Autonome Provinz Bozen, 2017; Bigi et al, 1990; Bundesamt für Landestopografie, 2005; Geologische Bundesanstalt, 2017a, 2017b). The Dolomites indenter (DI, the boundary is shown with a thick black line) is the South Alpine segment bounded by the Giudicarie Fault (GF) and the Pustertal‐Gailtal Fault (PGF).…”

Differential uplift on the boundary between the Eastern and the Southern European Alps: Thermochronologic constraints from the Brenner Base Tunnel

“…Simplified map and cross sections of the Periadriatic fault system between Passo Tonale (W) and the western part of the Tauern Window (E), based on Pomella et al (); The colour code indicates the tectonic affiliation of single faults to superordinate fault systems. Cross sections modified based on: (A–A′) Reiter et al (), (B–B′) Selverstone (), (C–C′ and D–D′) Pomella, Flöss, Speckbacher, Tropper, and Fügenschuh (), (E–E′) Viola, Mancktelow, Seward, Meier, and Martin (); one segment of the cross‐sectional scale bar equals 4 km; amAA, Alpine metamorphic Austroalpine units; anAA, Alpine non‐metamorphic Austroalpine units; BNF, Brenner normal fault; BMFZ, Brenner mylonitic fault zone; DAV, Defereggen‐Antholz‐Vals fault; JF, Jaufen fault; MMF, Meran‐Mauls fault; MSF, Mauls‐Sprechenstein fault zone; NGF, Northern Giudicarie fault; PGF, Pustertal‐Gailtal fault; PJ, Pejo fault; PN, Penninic nappes; PS, Passeier fault; SA, Southalpine units; SGF, Southern Giudicarie fault; SPN, Sub‐Penninic nappes; TF, Tonale fault; TW, Tauern Window [Colour figure can be viewed at wileyonlinelibrary.com]…”

Reuniting the Ötztal Nappe: the tectonic evolution of the Schneeberg Complex

“…They interpreted the Schneeberg Normal Fault Zone as a northwest-dipping ductile normal fault. Pomella et al (2016), in contrast, interpreted that this shear zone is only apparently a normal fault and in reality represents an originally southeast-dipping contact.…”

“…Many studies have dealt with the tectonics and metamorphism of the Schneeberg Complex and its relations to the surrounding units (e.g. Sander 1920Sander , 1929Schmidegg 1932Schmidegg , 1964Schmidt 1965;Baggio et al 1971;Zanettin 1971;Zanettin andJustin-Visentin 1971, 1980;Satir 1976;Helbig and Schmidt 1978;Mauracher 1980;Tessadri 1981;Hoinkes 1981Hoinkes , 1983Hoinkes et al 1987;Purtscheller et al 1987a, b;Thöni and Hoinkes 1987;van Gool et al 1987;Konzett and Hoinkes 1996;Sölva et al 2005; Zanchetta 2010; Krenn et al 2011;Pedevilla and Tropper 2012;Pomella et al 2016). South of the Schneeberg Complex a band of marbles and mica schists is called the Laas Series, due to its similarities to the marbles near Laas in the upper Vinschgau, belonging to the Campo Nappe.…”