Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees)
The definition of the structure and kinematics of the South-Pyrenean Frontal thrust, to the west of its westernmost outcrop in the External Sierras is the goal of this work. The methodology used is based on the construction and restoration of three balanced cross-sections. In addition to that, paleo...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)
2012-07-01
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| Series: | Geologica Acta |
| Subjects: | |
| Online Access: | https://revistes.ub.edu/index.php/GEOACTA/article/view/3815 |
| _version_ | 1827788075569250304 |
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| author | B. OLIVA URCIA A.M. CASAS E.L. PUEYO A. POCOVÍ JUAN |
| author_facet | B. OLIVA URCIA A.M. CASAS E.L. PUEYO A. POCOVÍ JUAN |
| author_sort | B. OLIVA URCIA |
| collection | DOAJ |
| description | The definition of the structure and kinematics of the South-Pyrenean Frontal thrust, to the west of its westernmost outcrop in the External Sierras is the goal of this work. The methodology used is based on the construction and restoration of three balanced cross-sections. In addition to that, paleomagnetic analyses are applied to unravel possible vertical axis rotations linked to thrust kinematics. Stepwise thermal demagnetizations of 22 new sites together with previously published data from 25 sites (sampled in Bartonian-Priabonian sediments) define reliable primary directions in the region allowing for potential vertical axis rotations estimation. The comparison between the deformed and the pre-deformational states in the cross-sections agrees with the paleomagnetic data in that neither gradient of shortening, nor significant vertical axis rotations can be invoked to explain the along-strike changes of the main structures (folds and thrusts) linked to the South-Pyrenean Frontal thrust, west of the western termination of the External Sierras. Therefore, these changes are here interpreted as the result of a wedge thrust in the Paleozoic basement, whose displacements in transferred to the Mesozoic-Tertiary cover through the Upper Triassic detachment level. This non-rotational kinematics of deformation implies a change of deformational style with respect to the External Sierras, where clockwise vertical axis rotations and gradient of shortening linked to rotational kinematics are found to be controlled by the Upper Triassic detachment level. |
| first_indexed | 2024-03-11T17:02:19Z |
| format | Article |
| id | doaj.art-77c3aafd03b54d9485dd9706d6f4daba |
| institution | Directory Open Access Journal |
| issn | 1696-5728 |
| language | English |
| last_indexed | 2024-03-11T17:02:19Z |
| publishDate | 2012-07-01 |
| publisher | Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB) |
| record_format | Article |
| series | Geologica Acta |
| spelling | doaj.art-77c3aafd03b54d9485dd9706d6f4daba2023-10-20T07:20:44ZengUniversitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)Geologica Acta1696-57282012-07-01102Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees)B. OLIVA URCIA0A.M. CASAS1E.L. PUEYO2A. POCOVÍ JUAN3Departamento de Ciencias de la Tierra. Universidad de Zaragoza. Pedro Cerbuna 12, 50009-Zaragoza, Spain. Fax: 976761106.Departamento de Ciencias de la Tierra. Universidad de Zaragoza. Pedro Cerbuna 12, 50009-Zaragoza, Spain. Fax: 976761106.Departamento de Geología y Geofísica del subsuelo. Oficina de Proyectos de Zaragoza IGME50006-Zaragoza, SpainDepartamento de Ciencias de la Tierra. Universidad de Zaragoza. Pedro Cerbuna 12, 50009-Zaragoza, Spain. Fax: 976761106.The definition of the structure and kinematics of the South-Pyrenean Frontal thrust, to the west of its westernmost outcrop in the External Sierras is the goal of this work. The methodology used is based on the construction and restoration of three balanced cross-sections. In addition to that, paleomagnetic analyses are applied to unravel possible vertical axis rotations linked to thrust kinematics. Stepwise thermal demagnetizations of 22 new sites together with previously published data from 25 sites (sampled in Bartonian-Priabonian sediments) define reliable primary directions in the region allowing for potential vertical axis rotations estimation. The comparison between the deformed and the pre-deformational states in the cross-sections agrees with the paleomagnetic data in that neither gradient of shortening, nor significant vertical axis rotations can be invoked to explain the along-strike changes of the main structures (folds and thrusts) linked to the South-Pyrenean Frontal thrust, west of the western termination of the External Sierras. Therefore, these changes are here interpreted as the result of a wedge thrust in the Paleozoic basement, whose displacements in transferred to the Mesozoic-Tertiary cover through the Upper Triassic detachment level. This non-rotational kinematics of deformation implies a change of deformational style with respect to the External Sierras, where clockwise vertical axis rotations and gradient of shortening linked to rotational kinematics are found to be controlled by the Upper Triassic detachment level.https://revistes.ub.edu/index.php/GEOACTA/article/view/3815Non-rotationalSouth-Pyrenean Frontal thrustVertical Axis RotationsGradient of shorteningBalanced and restored cross-sectionPaleomagnetism |
| spellingShingle | B. OLIVA URCIA A.M. CASAS E.L. PUEYO A. POCOVÍ JUAN Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) Geologica Acta Non-rotational South-Pyrenean Frontal thrust Vertical Axis Rotations Gradient of shortening Balanced and restored cross-section Paleomagnetism |
| title | Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) |
| title_full | Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) |
| title_fullStr | Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) |
| title_full_unstemmed | Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) |
| title_short | Structural and paleomagnetic evidence for non-rotational kinematics of the South Pyrenean Frontal Thrust at the western termination of the External Sierras (southwestern central Pyrenees) |
| title_sort | structural and paleomagnetic evidence for non rotational kinematics of the south pyrenean frontal thrust at the western termination of the external sierras southwestern central pyrenees |
| topic | Non-rotational South-Pyrenean Frontal thrust Vertical Axis Rotations Gradient of shortening Balanced and restored cross-section Paleomagnetism |
| url | https://revistes.ub.edu/index.php/GEOACTA/article/view/3815 |
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