The Huallaga foreland basin evolution: Thrust propagation in a deltaic environment, northern Peruvian Andes

Wilber Hermoza (1) , Stéphane Brusset (2) , Patrice Baby (1, 2) , Willy Gil , Martin Roddaz (2) , Nicole Guerrero (2) , Rolando Bolaños (3)

1 Peru Petro
2 LMTG - Laboratoire des Mécanismes et Transfert en Géologie
3 Laboratori d'Enginyeria Martima

The sub-Andean Huallaga basin is part of the modern retroforeland basin system of Peru. It corresponds to a thrust-and-fold belt superimposed on inverted and halokinetic structures and is characterized by Eocene Pliocene, thick synorogenic series that have controlled the burial history of petroleum systems. Sedimentological analysis and a sequentially restored cross-section based on seismic data and new field studies show three sequences of synorogenic deposits. The Eocene (Lower Pozo member) developed in shoreface environments, when the basin morphology corresponded to a foresag depozone linked to an orogenic unloading period. The Middle Eocene sequence (Upper Pozo member) developed in shallow marine environments and recorded a change in Andean geodynamics and the retroforeland basin system. The basin morphology corresponded to a foredeep depozone linked to an orogenic loading period. This configuration remained until the Middle Miocene (Chambira Formation). The Middle Miocene Pliocene sequence recorded the onset of the modern sub-Andean Huallaga basin that became a wedge-top depozone. Thrust propagation occurred in a deltaic environment, which evolved progressively to an alluvial system linked to the modern Amazon River.

Domaines: Sciences de la Terre

Wilber Hermoza, Stéphane Brusset, Patrice Baby, Willy Gil, Martin Roddaz, et al.. The Huallaga foreland basin evolution: Thrust propagation in a deltaic environment, northern Peruvian Andes. Journal of South American Earth Sciences, 2005, 19, pp.21-34. ⟨10.1016/J.JSAMES.2004.06.005⟩. ⟨hal-00648405⟩