Timing and kinematics of deformation in the Malaguide Complex, internal zone of the Betic Cordillera, southeast Spain

Abstract

The Betic Cordillera of southern Spain forms the westernmost of the Mediterranean Alpine orogenic belts and is divided, traditionally, into Internal and External Zones. In the External Zone fold and thrust belt, unmetamorphosed cover rocks of the Iberian margin were deformed from the early Miocene onward. In contrast, Internal Zone rocks are dominantly metamorphic and are generally assumed to have been deformed and metamorphosed in an Alpine event resulting from Late Cretaceous/Palaeogene convergence between Africa and Europe. In the Sierra Espuña, at the northern edge of the Internal Zone in the Eastern Betics, the uniquely preserved Permo‐Triassic to Miocene stratigraphy of the unmetamorphosed Malaguide Complex, offers a rare opportunity to date the Internal Zone deformation. Kinematic data, thrust geometries and structural facing of folds suggest that the imbricate thrust stack of Malaguide rocks formed as a result of NNW‐directed motion, within present geographical coordinates. A fossilized front to this thrust stack, preserved beneath a thick sequence of Oligocene conglomerates, indicates that the timing of the thrust deformation is late Eocene in age. Deformation propagated into the foreland basin in the late Oligocene with renewed thrusting. Subsequently, the whole stack has been folded into a N‐NW vergent regional recumbent fold, the Espuña fold, during the early Miocene.