Structure of the Southern Andes between 36-39ºS

ROJAS VERA, E.A.; ORTS, D.; SPAGNUOLO, M.; SAGRIPANTI, L.; GÍMENEZ, M.; RUIZ, F.; MARTÍNEZ, P.; ZAMORA VALCARCE, G.; BOTTESI, G.; FOLGUERA, A.; RAMOS, V. A.

Simposio; VIII ISAG; 2012

The Southern Andes were developed through a complex evolution that comprehended contractional and extensional stages since 110-90 Ma, when the South Atlantic ocean start opening (Godoy et al., 1999 ; Jordan et al., 2001; Charrier et al., 2002; Oncken et al., 2006).  The northern section is characterized by prominent basement structures, a relatively deep level of exhumation and a thick skinned orogenic front that conforms a topography with important areas over 2,000 m. Contrastingly, the southern part is formed by mildly inverted basement structures mainly restricted to the hinterland zone that determined a much lower topography than to the north, reaching locally 1,500-1,700 m. Through the construction of regional balanced cross sections across the Andes, constrained by field and geophysical data, variable contribution of main contractional stages was quantified.