Remagnetizations used to unravel large-scale fold kinematics: a case study in the Cameros Basin (Northern Spain)

The occurrence of a generalized remagnetization at 100 Ma makes the Cameros Basin, an 8 km thick Cretaceous extensional trough inverted during the Cenozoic, a perfect natural frame to apply paleomagnetic vectors to geometrical reconstructions. The widespread remagnetization that occurred between the...

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Detalles Bibliográficos
Autores: García-Lasanta, C., Casas-Sainz, Antonio M., Villalaín, Juan J., Oliva-Urcia, Belén, Mochales López, Tania, Speranza, Fabio
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/276710
Acceso en línea:http://hdl.handle.net/10261/276710
https://doi.org/10.1002/2016TC004459
Access Level:acceso abierto
Palabra clave:remagnetization
Basin inversions
Cameros Basin
unfolding
hinge migration
small circles intersection
Descripción
Sumario:The occurrence of a generalized remagnetization at 100 Ma makes the Cameros Basin, an 8 km thick Cretaceous extensional trough inverted during the Cenozoic, a perfect natural frame to apply paleomagnetic vectors to geometrical reconstructions. The widespread remagnetization that occurred between the extensional and compressional episodes, linked to low‐grade metamorphism, provides a tool to reconstruct the attitude of beds at the remagnetization time, thus giving a picture of basin geometry during the Cretaceous. This snapshot is compared with the present‐day geometry to constrain the large‐scale kinematic evolution of folds between these two stages. According to this methodology, a syncline, preinversion geometry of the sedimentary basin was determined and the position of its main axial surface was accurately located. Comparing with the present‐day, postinversion geometry, a northward hinge migration of around 5 km is inferred. This migration is the result of the southward back thrusting in the southern basin border, favored by the detachment level at the base of the Mesozoic cover. Conversely, the main northward directed thrust, which involved both the Paleozoic basement and the Mesozoic cover, did not significantly affect the internal structure of the basin in spite of its overall displacement of more than 20 km.