Sedimentation model of piggyback basins: Cenozoic examples of San Juan Precordillera, Argentina

SURIANO, JULIETA; LIMARINO, CARLOS OSCAR; TEDESCO, ANA MARÍA; ALONSO, MARÍA SUSANA

Geodynamic Processes in the Andes of Central Chile and Argentina.

Geological Society of London, Special Publications

Lugar: LONDRES; Año: 2014; p. 399 - 416

Abstract: Piggyback basins are one of the most important sediment storage systems for foredeep basins withinforeland basin systems, so understanding the dynamics of sediment accumulation and allocyclic changes is essential. Three alluvial systems are proposed here to depict sediment move- ment along the piggyback basin: piedmont, axial and transference systems. We propose differen- tiation between open continental piggyback basins that include a transference system that is able to deliver sediment to the foredeep and closed piggyback basins that are isolated. Two idealized models of sedimentation in piggyback basins are proposed. For open piggyback basins we identify four stages: (a) the incision stage; (b) the confined low accommodation system tract; (c) the high accommodation system tract; and (d) the unconfined low accommodation system tract. Meanwhile two stages are proposed for closed ones: (a) the high accommodation system tract; and (b) the low accommodation system tract. To test these models, Quaternary deposits and a Miocene unit are analysed. The first one is controlled by climatic changes, and the second is related to tectonic activity in Precordillera