02593nmc a2200193 4500 20260525050021.0 260224s xxu CD I116 64 0015469 Rocha, Emilio 55800 Cristallini, Ernesto O. 55801 Congreso de Exploración y Desarrollo de Hidrocarburos (9no. : 2014 nov. 3-7 : Mendoza) 54287 Cambios en el relieve como control estructural en la evolución de la faja subandina del sur de Bolivia 11/11/2016 ; 11/11/2016 25 p. Drainage network changes as a structural control in the evolution of the Subandean zone of southern Bolivia The Subandean zone of southern Bolivia is a typical thin-skinned fold and thrust belt with remarkable regularity in the geometry and spacing of the structures. This is typical feature of fold and thrust belts where the basement is not involved in deformation. However, when the structural geometry and evolution are analyzed in detail, many deviations from such regularity are evidenced. This paper has studied the processes that might have affected the development of some of the structures along the southern Subandean zone. Special attention is given to the La Vertiente structure, a thrust related fold with low relief developed at the latitude of Rio Pilcomayo. According to interpretation of growth strata based on 2D seismic lines and radiometric ages of Neogene tuffs, the beginning of deformation of this structure has been dated by several authors at around 6 Ma. Restoration of structural cross sections suggests that the La Vertiente structure was originated with a spacing of 65 km, which represents 2-3 times the maximum spacing that characterizes the rest of the structures of the southern Subandean zone. With the aim of explaining this "anomaly", different factors that could lead to an increase in the maximum spacing of this order have been analyzed. A model is presented in which increased capacity of erosion of the Rio Pilcomayo, as a result of the capture of a large drainage network area that previously was part of the Rio Parapeti drainage network, would have generated a dramatic decrease in the effective coefficient of basal friction of Silurian shales from the Kirusillas Formation. This change, in turn, would be responsible for the increase in spacing between structures that takes place at the La Vertiente structure. https://biblioteca.iapg.org.ar/ArchivosAdjuntos/CONEXPLOR2014/613-Cambiosenelrelieve.pdf CONGTP ddc 189842 189842 0 0 0 0 257661 BAAB BAAB CD I116 64 0015469 2026-03-06 200062088 0 CD I116 64 0015469 200062088 2026-03-06 00:20:00 2026-03-06 ARCHIVO