Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)

Mélange rocks outcrop widely in the central and western frontal sectors of the Betic Cordillera, as in many other collisional orogens where they form part of the accretionary wedges. Extrusion of Triassic plastic clays and evaporites was favored by the progressive accretion of the Betic External Zon...

Full description

Saved in:
Bibliographic Details
Main Authors: A. Ruiz‐Constán, A. Pedrera, J. Galindo‐Zaldívar, J. Pous, J. Arzate, F. J. Roldán‐García, C. Marin‐Lechado, F. Anahnah
Format: Article
Language:English
Published: Wiley 2012-08-01
Series:Geochemistry, Geophysics, Geosystems
Subjects:
Online Access:https://doi.org/10.1029/2012GC004153
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849709344585678848
author A. Ruiz‐Constán
A. Pedrera
J. Galindo‐Zaldívar
J. Pous
J. Arzate
F. J. Roldán‐García
C. Marin‐Lechado
F. Anahnah
author_facet A. Ruiz‐Constán
A. Pedrera
J. Galindo‐Zaldívar
J. Pous
J. Arzate
F. J. Roldán‐García
C. Marin‐Lechado
F. Anahnah
author_sort A. Ruiz‐Constán
collection DOAJ
description Mélange rocks outcrop widely in the central and western frontal sectors of the Betic Cordillera, as in many other collisional orogens where they form part of the accretionary wedges. Extrusion of Triassic plastic clays and evaporites was favored by the progressive accretion of the Betic External Zones, mixing rocks of different provenance and forming a synorogenic frontal mélange unit. MT data coupled with gravity data are a valid combined methodology to characterize the geometry of these mélange units, since the characterization of plastic rocks geometry is usually uncertain using seismic techniques. The results correlate well with known geological features (sedimentary basins, calcareous ranges, evaporitic rocks) and reveal the deep geometry. A resistive body, slightly dipping toward the SE, points to the continuity of the Iberian Massif below the Guadalquivir basin (2°) and the External Zones (6–8°). To the south, gravity models show the Iberian continental crust subducting below the Internal Zones with a roughly 20–35° slope. The main conductive bodies are related to the location of evaporitic rocks involved in the frontal mélange. They overlie the Iberian Massif and, southwards, the frontal Jurassic and Cretaceous limestone sequences of the External and Median Subbetics. In this setting, thick plastic rock units placed above the foreland could act as a lubricant facilitating continental subduction, and being progressively accreted toward a frontal mélange.
format Article
id doaj-art-c43b07e82f154368a221c2d974cb6d5a
institution DOAJ
issn 1525-2027
language English
publishDate 2012-08-01
publisher Wiley
record_format Article
series Geochemistry, Geophysics, Geosystems
spelling doaj-art-c43b07e82f154368a221c2d974cb6d5a2025-08-20T03:15:20ZengWileyGeochemistry, Geophysics, Geosystems1525-20272012-08-01138n/an/a10.1029/2012GC004153Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)A. Ruiz‐Constán0A. Pedrera1J. Galindo‐Zaldívar2J. Pous3J. Arzate4F. J. Roldán‐García5C. Marin‐Lechado6F. Anahnah7Géosciences Montpellier, Université Montpellier 2-CNRS, Place E. Bataillon, FR-34095 Montpellier, FranceInstituto Geológico y Minero de España, Ríos Rosas 23, ES-28003 Madrid, SpainInstituto Andaluz de Ciencias de la Tierra, CSIC–Universidad de Granada, ES-18071 Granada, SpainDepartament de Geodinàmica i Geofísica, Universitat de Barcelona, ES-08028 Barcelona, SpainCentro de Geociencias, UNAM, Campus Juriquilla, 76220 Queretaro, MexicoInstituto Geológico y Minero de España, Ríos Rosas 23, ES-28003 Madrid, SpainInstituto Geológico y Minero de España, Ríos Rosas 23, ES-28003 Madrid, SpainDepartamento de Geodinámica, Universidad de Granada, Campus Fuentenueva s/n, ES-18071 Granada, SpainMélange rocks outcrop widely in the central and western frontal sectors of the Betic Cordillera, as in many other collisional orogens where they form part of the accretionary wedges. Extrusion of Triassic plastic clays and evaporites was favored by the progressive accretion of the Betic External Zones, mixing rocks of different provenance and forming a synorogenic frontal mélange unit. MT data coupled with gravity data are a valid combined methodology to characterize the geometry of these mélange units, since the characterization of plastic rocks geometry is usually uncertain using seismic techniques. The results correlate well with known geological features (sedimentary basins, calcareous ranges, evaporitic rocks) and reveal the deep geometry. A resistive body, slightly dipping toward the SE, points to the continuity of the Iberian Massif below the Guadalquivir basin (2°) and the External Zones (6–8°). To the south, gravity models show the Iberian continental crust subducting below the Internal Zones with a roughly 20–35° slope. The main conductive bodies are related to the location of evaporitic rocks involved in the frontal mélange. They overlie the Iberian Massif and, southwards, the frontal Jurassic and Cretaceous limestone sequences of the External and Median Subbetics. In this setting, thick plastic rock units placed above the foreland could act as a lubricant facilitating continental subduction, and being progressively accreted toward a frontal mélange.https://doi.org/10.1029/2012GC004153Gibraltar Arcbroadband magnetotelluric datafrontal mélangegravity data
spellingShingle A. Ruiz‐Constán
A. Pedrera
J. Galindo‐Zaldívar
J. Pous
J. Arzate
F. J. Roldán‐García
C. Marin‐Lechado
F. Anahnah
Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
Geochemistry, Geophysics, Geosystems
Gibraltar Arc
broadband magnetotelluric data
frontal mélange
gravity data
title Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
title_full Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
title_fullStr Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
title_full_unstemmed Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
title_short Constraints on the frontal crustal structure of a continental collision from an integrated geophysical research: The central‐western Betic Cordillera (SW Spain)
title_sort constraints on the frontal crustal structure of a continental collision from an integrated geophysical research the central western betic cordillera sw spain
topic Gibraltar Arc
broadband magnetotelluric data
frontal mélange
gravity data
url https://doi.org/10.1029/2012GC004153
work_keys_str_mv AT aruizconstan constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT apedrera constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT jgalindozaldivar constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT jpous constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT jarzate constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT fjroldangarcia constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT cmarinlechado constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain
AT fanahnah constraintsonthefrontalcrustalstructureofacontinentalcollisionfromanintegratedgeophysicalresearchthecentralwesternbeticcordilleraswspain