Macro‐ and meso‐scale structural criteria for identifying pre‐thrusting normal faults within foreland fold‐and‐thrust belts: Insights from the Central‐Northern Apennines (Italy)

Abstract

Reliable macro-and meso-scale structural criteria for identifying pre-thrusting nor-

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 recent 2016 central Italy earthquake sequence (Bonini et al, ; Cheloni et al, ; Chiaraluce et al, ) pertains to this seismo‐tectonic framework. Deciphering whether extensional faulting developed in response to gravity during thrusting or to a regional extensional regime postdating contraction, and whether extensional fault zones are newly formed structures or reactivated structures inherited from either the passive margin or the foreland basin system environment, is not straightforward and is a matter of debate (e.g., Calamita et al, ; Coward et al, ; Ghisetti & Vezzani, ; Pace et al, ; Tavarnelli, ).…”

The Campotosto linkage fault zone between the 2009 and 2016 seismic sequences of central Italy: Implications for seismic hazard analysis

“…The Laga Basin sits on the faulted Jurassic-upper Miocene dominantly carbonate succession. The basin has a triangular shape and is located in the footwall of the major thrusts of the region, i.e., the Umbria-Marche-Sabina thrust zone (Mazzoli et al, 2005; see also Carminati and Doglioni, 2012), or Monti Sibillini thrust to the east, and the Gran Sasso thrust to the south (Calamita et al, 2018). These thrusts were active during the deposition of the Laga Formation, which shows lateral facies variations marked by the transition from channelized deposits in the north-western portion of the basin to lobe deposits in its eastern and south-eastern part (Milli et al, 2009;Marini et al, 2011).…”

“…Both of these faults display evidence of pre-thrusting extensional activity, in the form of: (a) thickness variations of stratigraphic units across the fault, recording syn-rift sediment accommodation on top of the downthrown hanging-wall block, and (b) intense folding of the hanging-wall sedimentary fill in proximity to the fault surface, indicating buttressing against the preexisting mechanical interface represented by the fault during subsequent orogenic shortening (Calamita et al, 1998(Calamita et al, , 2018Mazzoli et al, 2002;Scisciani et al, 2002;Butler et al, 2006;Withjack et al, 2010;Brogi, 2016). Buttressing may affect both hanging wall and footwall blocks, depending on the competence of the rocks (Calamita et al, 2018). In our instance, the lithologies more prone to buttressing are those of the pelitic-arenaceous association of the Laga Formation, that in fact show intense folding in the southern part of the MGF hanging wall.…”

A Multi-Disciplinary Approach to the Study of Large Rock Avalanches Combining Remote Sensing, GIS and Field Surveys: The Case of the Scanno Landslide, Italy

“…The main valley is deeply incised into a pelitic-arenaceous bedrock representing Neogene foredeep sequences [31]. The eastern margin of the Lazium-Abruzzo carbonate shelf is tectonically juxtaposed to the calcareous-marly Mount Genzana slope-to-basin domain along a major NNW-SSE tectonic lineament (Profluo-Tasso-Sagittario line), which includes the DMG fault zone [31][32][33][34][35][36]. From the late Miocene onwards, the above-mentioned domains have been affected by deformation which resulted in: (i) pre-thrusting normal faulting related to foreland flexural processes (DMG fault); (ii) pervasive faulting combining Late Miocene-Early Pliocene thrusting (Montagna Grande thrust); (iii) Pliocene strike-slip tectonics (DMG fault); (iv) Pleistocene normal faulting (local reactivation of the DMG fault in the Scanno area).…”