Role of basin width variation in tectonic inversion: insight fomr analogue modelling and implications for the tectonic inversion of the Abanico Basin, 32º-34ºS, Central Andes

JARA PAMELA; LIKERMAN JEREMIAS; WINOCUR, DIEGO; GHIGLIONE MATÍAS; CRISTALLINI ERNESTO; PINTO, LUISA; CHARRIER REYNALDO

GEOLOGICAL SOCIETY OF LONDON SPECIAL PUBLICATION

The Geological Society of London

Año: 2014 vol. 399 p. 24 - 50

0305-8719

We use analogue modelling to investigate the response of compressional deformationsuperimposed on an extensional basin with along-strike changes in width. Parameters describedinclude extension and shortening distribution and directions, orientation of structures and degreeof basin inversion. Two types of model are presented: in the first (Type I), an extensional basinis constructed with variable width (applying differential extension) and subsequently invertedby homogeneous shortening; in the second (Type II), an extensional basin with constant widthis subsequently inverted by inhomogeneous shortening (differential compression). From our observations, we compare both types of model to structural patterns observed in some natural cases from the Central Andes. Both models generate oblique structures, but in the Type II model a significant rotation is characteristic. Our results suggest that in the Central Andes region between 32º and 33ºS, the Abanico Basin may correspond to a basin of smaller area compared to the larger basin south of 33ºS. Our Type I model further explains some patterns observed there, from which we conclude that the control exercised by the width of a pre-existing basin should be considered when interpreting the geological evolution of that area of the Andes.