Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Journal of South American Earth Sciences 21-34 deltaic and estuarine deposits eocene foreland basing Huallaga basin miocenc Peru petroleum systems sub Andean 2005 PAR00000447 ENG Journal of South American Earth Sciences 0895-9811 ISI:000231583800003 1 10.1016/j.jsames.2004.06.005 https://www.documentation.ird.fr/hor/PAR00000447 19 Horizon (IRD) 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 it wedge-top depozone. Thrust propagation occurred in a deltaic environment, which evolved progressively to an alluvial system linked to the modern Amazon River. (c) 2005 Published by Elsevier Ltd. 064