Unraveling structural features related to different orogenic cycles is fundamental for a better understanding of collisional orogens, particularly concerning the role of structural inheritance and extent of crustal reworking. In the Internal Domains of the Betic Cordillera, the geometry and kinematics of pre-Alpine contractional deformation in the Paleozoic basements are rather poorly known. At Ardales, a strongly deformed area corresponding to part of the Alpine suture zone of the Betic Cordillera, the Malaguide Complex consists of two distinct, superposed Alpine tectonic units, including both Paleozoic basement and Mesozoic-Tertiary cover rocks. Within the Alpine footwall unit, stratigraphic data document a tectonic superposition of two subunits made of different Paleozoic successions, which was later fossilized by Triassic redbeds. Structural analysis indicates that the contact between these subunits is an east-directed overthrust and that the internal structure of the lower subunit is consistent with bulk noncoaxial strain dominated by top-to-the-E shearing. These features show a marked contrast with the well-known Alpine nappe transport direction to the N-NW, with tectonic features developed along the Internal-External Domain boundary and with the structural trends obtained from the analysis of Mesozoic-Tertiary Malaguide rocks of the area. This study demonstrates that east-directed thrusting and shearing within Paleozoic Malaguide rocks resulted from Variscan tectonics and that careful, detailed, and integrated stratigraphic and structural analysis is necessary to avoid confusion between older and newer orogenic cycles in the Internal Domain Units of the Betic Cordillera.

Variscan tectonics in the Malaguide Complex (Betc Cordillera, southern Spain): stratigraphic and structiural constraints from the Ardales area (Province of Malaga). Part II: Structure.

PERRONE, VINCENZO;
2009-01-01

Abstract

Unraveling structural features related to different orogenic cycles is fundamental for a better understanding of collisional orogens, particularly concerning the role of structural inheritance and extent of crustal reworking. In the Internal Domains of the Betic Cordillera, the geometry and kinematics of pre-Alpine contractional deformation in the Paleozoic basements are rather poorly known. At Ardales, a strongly deformed area corresponding to part of the Alpine suture zone of the Betic Cordillera, the Malaguide Complex consists of two distinct, superposed Alpine tectonic units, including both Paleozoic basement and Mesozoic-Tertiary cover rocks. Within the Alpine footwall unit, stratigraphic data document a tectonic superposition of two subunits made of different Paleozoic successions, which was later fossilized by Triassic redbeds. Structural analysis indicates that the contact between these subunits is an east-directed overthrust and that the internal structure of the lower subunit is consistent with bulk noncoaxial strain dominated by top-to-the-E shearing. These features show a marked contrast with the well-known Alpine nappe transport direction to the N-NW, with tectonic features developed along the Internal-External Domain boundary and with the structural trends obtained from the analysis of Mesozoic-Tertiary Malaguide rocks of the area. This study demonstrates that east-directed thrusting and shearing within Paleozoic Malaguide rocks resulted from Variscan tectonics and that careful, detailed, and integrated stratigraphic and structural analysis is necessary to avoid confusion between older and newer orogenic cycles in the Internal Domain Units of the Betic Cordillera.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11576/2302291
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