Publication Date:
2017-04-08
Description:
The occurrence of a generalized remagnetization at 100 Ma makes the Cameros basin, a 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 the 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, pre-inversion geometry of the sedimentary basin was determined and the position of its main axial surface was accurately located. Comparing with the present-day, post-inversion geometry, a northwards hinge migration of around 5 km is inferred. This migration is the result of the southwards backthrusting in the southern basin border, favored by the detachment level at the base of the Mesozoic cover. Conversely, the main northwards-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.
Print ISSN:
0278-7407
Electronic ISSN:
1944-9194
Topics:
Geosciences
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