Inheritance of Jurassic rifted margin architecture into the Apennines Neogene mountain building: a case history from the Lucretili Mts. (Latium, Central Italy)

Abstract

The western Lucretili Mts. in the central Apennines (Latium, Italy) have been recently re-mapped in great detail and are the subject of combined stratigraphic, sedimentological and structural investigations. In this paper, we present a new stratigraphic interpretation of the Jurassic paleogeography of western Lucretili Mts., where a rift-derived intrabasinal paleo-high of the Alpine Tethys has been identified for the first time by means of facies analysis and biostratigraphic dating. Recognised facies associations, combined with dated stratigraphic sections, allow to define the morphology of the structural paleo-high and to identify the associated gravity-driven deposits (olistoliths) accumulated in the surrounding basin. Furthermore, we investigated the modes of interaction between Jurassic extensional structures and the subsequent contractional patterns developed during the Tertiary mountain building. In detail, the role played during Apennines tectonics by the paleo-escarpments bounding the paleo-high and by the surrounding olistoliths has been analysed. The paleo-escarpments either acted as focussing features for ENE-directed frontal thrust ramp localisation and were offset with small shortening amounts or reactivated as NNE striking high angle transpressional faults or preserved the original geometries as a result of variable orientation of paleo-escarpments with respect to the Neogene compressive stress field (with ENE oriented sigma1). Newly formed ENE striking tear faults connect these either inherited or neo-formed discontinuities. This complex stratigraphic and structural pattern is substantially different from the previous interpretations of this portion of the central Apennines based on a hypothesised layer-cake stratigraphy deformed by neo-formed Neogene thrusts. This contribution strengthens the importance of integrating facies analyses and structural investigations to detect the influence of pre-orogenic structures on compressive structural patterns, in an area where commercial seismic lines are not available and cannot help in reconstructing the subsurface geometries. © 2011 Springer-Verlag

Fault-controlled dolomitization in the Montagna dei Fiori Anticline (Central Apennines, Italy): record of a dominantly pre-orogenic fluid migration

“…Condensed pelagic limestones of the Bugarone Formation (Lower Pliensbachian to Lower Tithonian; "Bugarone Group" in Pierantoni et al, 2013) occur at the top of the Calcare Massiccio Formation where it formed fault-controlled highs marking the regional drowning of the carbonate platform (Santantonio and Carminati, 2011). The pelagic limestones of the Corniola Formation (Sinemurian to Toarcian; Colacicchi et al, 1975;Morettini et al, 2002;Bosence et al, 2009;Marino and Santantonio, 2010;Brandano et al, 2016) occur within the fault-controlled (half)grabens in lateral continuation with the Calcare Massiccio Formation. The Corniola Formation in the lower part consists of turbiditic lobes which originated from tectonic brecciation of the Calcare Massiccio Formation.…”

Syn‐Contractional Overprinting Between Extension and Shortening Along the Montagna Dei Fiori Fault During Plio‐Pleistocene Antiformal Stacking at the Central Apennines Thrust Wedge Toe

“…The fundamental role of passive margin tectono‐sedimentary architectures in thrust wedges produced by plate‐motion reversal and continental collision is well established in the geological literature. Preservation of syn‐rift tectono‐sedimentary inheritance is commonly accepted in most foreland thrust‐fold belts, including the Apennines (Bertotti et al, ; Bollati et al, ; Bonini et al, ; Butler, ; Calamita et al, ; Cardello & Doglioni, ; Cosentino et al, ; Coward et al, ; Hayward & Graham, ; Marchegiani et al, ; Pierantoni et al, ; Roure et al, ; Scisciani et al, ; Tavani et al, ; Tavarnelli, ). Moreover, the evolution of foreland basin systems ahead of thrust‐fold belts typically includes formation of extensional fault zones during lithosphere bending, which can influence the depositional patterns of syn‐orogenic sediments (e.g., Scisciani, Calamita, et al, ).…”

Geological map of the central part of Narni-Amelia Ridge (Central Apennines, Italy)

“…horst-blocks, palaeoescarpments, olistoliths). In particular, the Jurassic structural highs characterise the hangingwall blocks of the thrusts over-thrusting the surrounding basinal successions and their margins are usually displaced with small shortening amounts by frontal thrusts or lateral ramps (Bollati et al, 2012;Cipriani, 2016). This is clear near Amelia, where the southern margin of the homonymous PCP overthrusts through a lateral ramp onto basin-fill succession onlapping it.…”