Kinematics of Overthrusting in the Southern Pyrenees, Catalonia

Eduard Clavell, John E. Kennedy, Albert Martinez, Jaume Verges

The emplacement of allochthonous sheets in the overthrust belt that forms the southern flank of the Pyrenees, through the Catalan region of Spain, began in Late Cretaceous time and continued into the Oligocene. The thrust system is interpreted as an emergent, imbricate fan in the front, backed by antiformal stacking northward toward the rear. This belt is limited to the south by the Vallfogona thrust, which forms the sole thrust of the whole system, and by the Ribes-Camprodon thrust to the north. Thrusting has occurred as a sequence of foreland-directed piggy-back movements. However, the earliest formed allochthonous sheets were emplaced before the duplex formation, which appears to have occurred largely after the early Eocene. The effect of the thrust movements was to displace the ma ine Eocene depocenter southward on the Catalan foreland, culminating in steepened dips, related to late Eocene and Oligocene movements along these faults, within the molasse deposits which represent the final infilling of the basin. Out-of-sequence thrusting, noted along the Ribes-Camprodon thrust and leading to the final emplacement of the allochthonous sheet of Montgri, is also related to these latest tectonic movements.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.