Restricted rifting and its coexistence with compressional structures: results from the CROP 3 traverse (Northern Apennines, Italy)

Abstract

A geological interpretation of the deep seismic reflection line CROP 3 (Italian program CROsta Profonda: deep crust, profile no. 3), which crosscuts the Northern Apennines from the Tyhrrenian to the Adriatic coast, is presented. The profile images the lithosphere up to 15 s TWT and highlights several peculiarities: (a) the lower crust is bedded by discontinuous sub parallel reflective markers which terminate at ≈ 7 s beneath the western side of the profile; (b) in the same area a notable reflection is recognizable at 10 s and is interpreted as the top of the asthenosphere; (c) east‐plunging shear zones are recognizable throughout the crust. By contrast, the Adriatic (outer) side of this line shows: (a) reflections deepening westward, from 13 to 15 s TWT, related to the base of the crust (33–38 km depth); (b) the absence of thick bedding of reflective markers within the lower crust; and (c) tectonic structures affecting the basement which are different from those which deform the cover of the Northern Apennines. Geological interpretation is based on the eastward migration of ductile shear zones which have been recognized on the seismic line. The bending of the outer zone crust is considered to be a consequence of the rifting process with the application of pushing forces against the Adriatic lithosphere which cannot escape toward east.

Faults linkage, damage rocks and hydrothermal fluid circulation: Tectonic interpretation of the Rapolano Terme travertines (southern Tuscany, Italy) in the context of Northern Apennines Neogene-Quaternary extension

“…In accordance with the authors which hypothesise that extensional tectonics affected the Northern Apennines since the Early-Middle Miocene (Jolivet et al 1990;Bertini et al 1991;Carmignani et al 1994;Liotta et al 1998), the Quaternary extensional tectonics could be attributed to a late event following the widespread Pliocene extensional activity which caused the development of the Tuscan Neogene basins, and can be related to differentiated vertical movement of the southern Tuscany continental crust which is associated with the uplift affecting the inner Northern Apennines (Bartolini et al 1983;Pasquarè et al 1983;Dallmayer et al 1995;Dallmayer & Liotta 1998).…”

“…(1991),Carmignani et al (1994) andLiotta et al (1998), in the inner Northern Apennines (i.e. northern Tyrrhenian Basin and southern Tuscany) the extensional tectonics started in the Early-Middle Miocene and produced thinning of the continental crust down to 22 km(Decandia et al 1998, and references therein).The Rapolano Terme area is located in southern Tuscany (Figs.…”

The Mesozoic continental rifting in the Mediterranean area: insights from the Verrucano tectofacies of southern Tuscany (Northern Apennines, Italy)

“…This tectonic unit was affected by two Alpine tectono-metamorphic events of low-greenschist-facies grade (Franceschelli et al 1986;Costantini et al 1988;Elter and Pandeli 1990;Corsi et al 2001) and subsequent weak folding (Corsi et al 2001) and faulting (Liotta et al 1998;Decandia et al 2001 and reference therein). Additionally, evidence of HP-LT metamorphism of Verrucano Group rocks has been documented in the Argentario Mount and Leoni Mount areas (Theye et al 1997;Giorgetti et al 1998;Brunet et al 2000).…”

Modeling Highly Buoyant Flows in the Castel Giorgio: Torre Alfina Deep Geothermal Reservoir

“…The complex geologic and tectonic settings of this area have been studied by several authors ( [51][52][53][54] and references therein).…”