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)

Terra Nova ◽  
2017 ◽  
Vol 30 (1) ◽  
pp. 50-62 ◽  
Author(s):  
Fernando Calamita ◽  
Alessandra Di Domenica ◽  
Paolo Pace
Keyword(s):  
Northern Apennines ◽  
Normal Faults ◽  
Thrust Belts ◽  
Fold And Thrust Belts ◽  
Meso Scale

scholarly journals Cambios estructurales causados por los buzamientos de rampas laterales en cinturones fallados y plegados

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Miguel Ángel Orjuela ◽  
Dilan Arturo Martínez-Sánchez ◽  
Giovanny Jiménez
Keyword(s):  
Strike Slip ◽  
Normal Faults ◽  
Rigid Block ◽  
Tectonic Structures ◽  
Thrust Belts ◽  
Analogue Models ◽  
Fold And Thrust Belts ◽  
Transverse Zone ◽  
Transverse Zones ◽  
Direction Opposite

Transverse zones are tectonic structures parallel or oblique to the shortening direction. Lateral ramps are inherited tectonic structures and are comprised in a transverse zone. During shortening transverse zones are usually confused with simple strike-slip faults. We evaluated 36 analogue models under brittle conditions using two frontal ramps connected by a lateral ramp at different inclinations (30°, 45°, and 60°) to identify lateral ramps characteristics in the fold and thrust belts. The experiments were conducted in a subduction-type sandbox, using dry sand and a rigid block, representing a brittle crust and the backstop. During shortening, faults and folds related grow parallel to frontal ramps. Significative plunges correlate with the inclination of the lateral ramp. The oblique faults dipped along the direction opposite to the lateral ramp, while the normal faults parallel to the lateral ramp only occurred when linked to lateral ramps with high inclinations. The inclination of the lateral ramp controls the plunge and rotation of the folds and thrust structures. Regardless of the lateral ramp inclinations, in map view, the main characteristics used to identify lateral ramps are i) disrupted structures along the strike in the lateral ramp area and ii) oblique faults related to frontal ramp structures.

Behaviour of minor arcuate shapes hosted in curved fold-and-thrust belts: an example from the Northern Apennines (Italy)

2019 ◽  
Vol 156 (9) ◽  
pp. 1547-1564 ◽  
Author(s):  
Sara Satolli ◽  
Simone Agostini ◽  
Fernando Calamita
Keyword(s):  
Structural Analysis ◽  
Vertical Axis ◽  
Local Scale ◽  
Northern Apennines ◽  
Deformation Mechanisms ◽  
Inversion Tectonics ◽  
Thrust Belts ◽  
Fold And Thrust Belts

AbstractArcuate fold-and-thrust belts have been extensively studied in the literature. Less attention, however, has been paid to the characteristics of local-scale arcuate structures, meaning 5–10 km long fold or thrust traces that display map-view curvature. Nevertheless, detailed investigation of small arcuate structures hosted in major arcs can contribute to understanding the pervasiveness of deformation mechanisms. We performed a combined geological and palaeomagnetic study on 21 sites from ac. 60 km2area in the Northern Apennines in order to analyse minor arcs at a kilometric scale. As evidenced by the geological and structural analysis performed on the 21 sites, the fold axial trend changes from N–S to NW–SE in the study area. The comparison with palaeomagnetic results shows the lack of correlation between vertical axis rotations and fold axial trends. As a consequence, the minor arcuate shapes of thrusts and related folds are interpreted as mostly primary features inherited from the geometry of the palaeomargin, represented by pre-orogenic faults, according to a context of inversion tectonics.

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