Strain partitioning and relief segmentation in arcuate fold-and-thrust belts: a case study from the western Betics

Strain Partitioning and Localization Due To Detachment Heterogeneities in Fold‐and‐Thrust Belts of Progressive Arcs: Results From Analog Modeling

“…Such diapirs are expected all along the betic fold‐and‐thrust belt (Berastegui et al., 1998; Nieto et al., 1992), although they are hardly identified probably due to complex structures formed by higher shortening in the apical part of the Gibraltar arc. Such pre‐deformational diapirs might have played a key role on the nucleation and development of normal and strike‐slip fault zones along the Betic fold‐and‐thrust belt strike for example, Balanyá et al., 2007; Jiménez‐Bonilla, Expósito, et al., 2017) as observed in our Models 1 to 3 (Figures 1, 4, and 11a). In this regard, traverse faults along the Betics are related to the widespread Triassic evaporites, which could be associated with pre‐deformational diapirs, that influenced the localization of major fault zones, such as the Ubrique Normal Fault Zone (UNFZ), the Ronda Basin normal faults or the Tíscar Fault Zone (Jiménez‐Bonilla et al., 2015, Jiménez‐Bonilla, Expósito, et al., 2017; Sanz de Galdeano et al., 2006; Figure 11a).…”

“…Such pre‐deformational diapirs might have played a key role on the nucleation and development of normal and strike‐slip fault zones along the Betic fold‐and‐thrust belt strike for example, Balanyá et al., 2007; Jiménez‐Bonilla, Expósito, et al., 2017) as observed in our Models 1 to 3 (Figures 1, 4, and 11a). In this regard, traverse faults along the Betics are related to the widespread Triassic evaporites, which could be associated with pre‐deformational diapirs, that influenced the localization of major fault zones, such as the Ubrique Normal Fault Zone (UNFZ), the Ronda Basin normal faults or the Tíscar Fault Zone (Jiménez‐Bonilla et al., 2015, Jiménez‐Bonilla, Expósito, et al., 2017; Sanz de Galdeano et al., 2006; Figure 11a). Thus, the localization of extension associated with pre‐deformational diapirs could be responsible for the development of intermontane basins along the Betics such as the Ronda basin (Figure 11a).…”

“…However, the distribution of this viscous layer is neither uniform nor homogeneous in natural cases, which may be key to interpreting structural style, including cross‐section and plan view geometries, strain localization and evolution along time of fold‐and‐thrust belts. This heterogeneous distribution is observed in many natural cases of progressive arcs by the presence of changes in the frictional properties of the detachment layer (e.g., Gibraltar arc: Vera, 2004; Chalouan et al., 2008), variations in the thickness of the detachment layer (e.g., Gibraltar arc: Vera, 2004; Crespo‐Blanc, 2008; Crespo‐Blanc et al., 2012; Barcos et al., 2015; Jiménez‐Bonilla et al., 2015, 2016; 2017b), the presence of pre‐deformational diapirs (e.g., Gibraltar arc: Nieto et al., 1992; Pedrera et al., 2014; Jiménez‐Bonilla et al., 2015, or Sulaiman arc: Rubinat et al., 2013; Kokinou et al., 2017; Najafi et al., 2018; Hassanpour et al., 2018) and/or the existence of detachment layer pinch‐outs (e.g., Zagros: Bahroudi & Koyi, 2003; Burkhard & Sommaruga, 1998; Hindle & Burkhard, 1999; Livani et al., 2018; McQuarrie, 2004; Ruh et al., 2017).…”

Tectonics may affect closed watersheds used to monitor climate change and human activity effects

“…Sinclair et al, 2017;Willett et al, 2001;Winterberg & Willett, 2019). The Betic chain, which is the northern branch of the Gibraltar arc (Figure 1), is an active orogen that builds up a young and changing relief (Azañón et al, 2012(Azañón et al, , 2015Civiero et al, 2020;Jiménez-Bonilla et al, 2015;Jiménez-Bonilla et al, 2017). Tectonic uplifting due to the Gibraltar arc formation provoked the closure of the Atlantic-Mediterranean gateway at 5.6 My giving rise to the Messinian Salinity Crisis (MSC, e.g.…”

“…(a) Schematic tectonic map of the Iberian peninsula with the main active orogenic fronts and (b) the main Mediterranean‐Atlantic divide and related playa lakes in the structural context of the western Betics (modified from Jiménez‐Bonilla et al, 2017). Dextral strike‐slip shear zones: ABSZ: Algodonales‐Badolatosa Shear Zone; TSZ: Torcal Shear Zone.…”