Paleomagnetic analysis from the Balzes anticline (Southern Pyrenees):: vertical-axis rotations and kinematics implications .
- Autores: A. Rodríguez-Pintó, Emilio L. Pueyo Morer, Andrés Pocoví Juan, Antonio Barnolas Cortina
- Localización: Trabajos de geología, ISSN 0474-9588, Nº 30, 2010, págs. 169-175
- Idioma: inglés
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Resumen
The Balzes anticline is a complex structure outcropping in the eastern part of the ExternalSierras (southwestern Pyrenees). It is a representative oblique structure of this area, where many N-Strending anticlines are parallel to the main stretching direction. Paleomagnetic analyses allow a preliminarykinematics model to be proposed for this structure. Twelve paleomagnetic sites (mostly derivedfrom magnetostratigraphic analysis) were sampled to calculate rotation magnitudes in both anticlinelimbs. A Characteristic paleomagnetic component, deduced from detailed TH and AF demagnetizations,unblocks up to 570 °C. Rotation ranges from 33° clockwise (CW) to 18º counterclockwise(CCW) are detected with a primary signal (with inclination error). This preliminary dataset permits usto propose a new geometric and kinematics model; the effect of the sedimentary wedge (decreasingsouthwards) together with E-W fold interference, a slow lateral transference of the deformation (rotation)and the low angle thrusting, generate a conical anticline in its northern part passing to a cylindricalstructure southwards. This preliminary model will be improved by a denser network of paleomagnetic,seismic, structural and stratigraphic data, which will lead us to determine the geometry andkinematics of this anticline.
