Early Tertiary orogenic evolution of the southern Central Andes as reflected by the detrital record preserved in the Puna Plateau and Eastern Cordillera of NW Argentina

• Applicant: Professor Manfred Strecker, Ph.D., since 8/2007
• Subject Area: Palaeontology
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 28054419

One of the key scientific problems in Geosciences today is centred on the relationships between processes acting in the deep earth (lithosphere) versus processes acting at shallower levels (in the crust) and at the surface. It is not clear if or how such processes are acting together and whether or not a coupling exists. Understanding the relationships between deep Earth and surficial processes is of fundamental importance if we want to understand Earth dynamics. Mountain belts and related foreland basins are the result of this complex interaction and provide a natural laboratory to investigate the relationships between endogenic and exogenic forces. A foreland basin system is genetically linked to its adjacent mountain belt and provides unique, long-term archives of information about deep Earth processes (subsidence) and surficial processes (sediment deposition and weathering). The magnitude of subsidence, the shape of the sedimentary fill and the source of detrital sediments in foreland basins depends on the location and size of the topographic load, the mode of compressional stresses acting during sedimentation and on the type, relief and climate of the source-basin system. Sedimentary basins preserved within the Puna Plateau and Eastern Cordillera in NW Argentina provide one of the earliest records of compressional deformation associated with Andean mountain building. These basins contain >4 km-thick Paleogene clastic sediments that are exceptionally well exposed. Studies in contemporary sedimentary basins in southern central Bolivia (Altiplano) lead to the proposition that a foreland basin system, i.e. contractional deformation, already started in the Paleocene and that a significant amount of foreland lithosphere was thrusted underneath the Andean crust leading to the building of the orogenic belt. A multidisciplinary study of time equivalent basins in NW Argentina shall provide new data that will allow testing and potential validation of this model. This in turn will permit quantification of source paleogeography, exhumation, relief, climate and mechanisms of basin formation in this part of the Andes, in a key time that is the Paleogene, contributing greatly to our understanding of mountain building associated to the Puna-Altiplano Plateau and Eastern Cordillera system in the early Tertiary.

• DFG Programme: Research Grants
• International Connection: Argentina, USA
• Participating Persons: Professor Dr. Ricardo Alonso; Professor Dr. Peter DeCelles
• Ehemalige Antragstellerin: Professorin Dr. Barbara Carrapa, until 8/2007