TY - JOUR
T1 - Geomorphological evolution of the Tilcara alluvial fan (Jujuy Province, NW Argentina)
T2 - Tectonic implications and palaeoenvironmental considerations
AU - Sancho, Carlos
AU - Peña, José Luis
AU - Rivelli, Felipe
AU - Rhodes, Ed
AU - Muñoz, Arsenio
PY - 2008/7
Y1 - 2008/7
N2 - The development and evolution of the Tilcara alluvial fan, in the Quebrada de Humahuaca (Andean Eastern Cordillera, NW Argentina), has been analysed by using geomorphological mapping techniques, sedimentological characterisation of the deposits and OSL chronological methods. It is a complex segmented alluvial fan made up of five evolutionary stages (units Qf1, Qf2, Qf3, Qf4 and Qf5) developed under arid climatic environments as well as compressive tectonic conditions. Segmentation processes, including aggradation/entrenchment cycles and changes in the location of the depositional lobe, are mainly controlled by climatic and/or tectonic changes as well as channel piracy processes in the drainage system. Alluvial fan deposits include debris flows, sheet flows and braided channel facies associated with high water discharge events in an arid environment. The best mean OSL age estimated for stage Qf2 is 84.5 ± 7 ka BP. In addition, a thrust fault affecting these deposits has been recognized and, as a consequence, the compressive tectonics must date from the Upper Pleistocene in this area of the Andean Eastern Cordillera.
AB - The development and evolution of the Tilcara alluvial fan, in the Quebrada de Humahuaca (Andean Eastern Cordillera, NW Argentina), has been analysed by using geomorphological mapping techniques, sedimentological characterisation of the deposits and OSL chronological methods. It is a complex segmented alluvial fan made up of five evolutionary stages (units Qf1, Qf2, Qf3, Qf4 and Qf5) developed under arid climatic environments as well as compressive tectonic conditions. Segmentation processes, including aggradation/entrenchment cycles and changes in the location of the depositional lobe, are mainly controlled by climatic and/or tectonic changes as well as channel piracy processes in the drainage system. Alluvial fan deposits include debris flows, sheet flows and braided channel facies associated with high water discharge events in an arid environment. The best mean OSL age estimated for stage Qf2 is 84.5 ± 7 ka BP. In addition, a thrust fault affecting these deposits has been recognized and, as a consequence, the compressive tectonics must date from the Upper Pleistocene in this area of the Andean Eastern Cordillera.
KW - Andean Cordillera
KW - Arid environments
KW - OSL dating
KW - Thrust tectonics
KW - Tilcara alluvial fan
KW - Upper Pleistocene
UR - http://www.scopus.com/inward/record.url?scp=48349127073&partnerID=8YFLogxK
U2 - 10.1016/j.jsames.2008.03.005
DO - 10.1016/j.jsames.2008.03.005
M3 - Article
SN - 0895-9811
VL - 26
SP - 68
EP - 77
JO - Journal of South American Earth Sciences
JF - Journal of South American Earth Sciences
IS - 1
ER -