| Eocene wedge-top strata in southern Peru captured multiple tectonic events during the
early Andean Orogeny. In the Altiplano region of the Central Andes, studies often overlook
Cenozoic mountain building that preceded rapid orogenic growth during the Miocene, and as
such many of the processes associated with earlier events are poorly defined. We couple the
stratigraphic record preserved in the Anta Formation with new U-Pb detrital zircon data to better
understand the timing and style of basin development, the provenance and recycling history of
sediment, and the tectonic processes that exert influence over sedimentation in wedge-top basins.
Our study reveals over 2 km of conglomerate deposition in alluvial and fluvial settings driven by
unroofing of the Western Cordillera between 40 and 36 Ma before establishment of the inboard
Andahuaylas-Yauri Batholith and Anta Volcanic Arc that persisted until 30 Ma.
Keywords: wedge-top, Peru, detrital zircon, unroofing, conglomerate, alluvial fan |