Structural style of the Chos Malal fold and thrust belt, Neuquén Basin, Argentina: relationship between thick- and thin-skinned tectonics.

NATALIA SÁNCHEZ; MARTÍN TURIENZO; FERNANDO LEBINSON ; VANESA ARAUJO; ISABELLE COUTANDAND ; LUIS DIMIERI

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 64 p. 399 - 417

0895-9811

The Andes are the outcome of a complex tectonic evolution consequence of different processes that acted differentially along the continental margin. Particularly, the Andean compression deformed Paleozoic and Mesozoic rocks forming different fold and thrust belt that together form the Neuquén Precordillera. In particular, the Chos Malal fold and thrust belt is located between 37° and 37° 30´S, in the northwestern sector of Neuquén Province. This part of the Andes is the southern prolongation of FTB Malargüe and the northern expression of FTB Agrio, bounded from the latest by the Cortaderas lineament (Ramos 1978). This orogenic belt deformed Mesozoic fill of the Neuquén basin and is limited by two morphostructural hights: Cordillera del Viento towards west and Macizo del Tromen towards east (Bracaccini 1970).In this contribution, we analyze the structures present in the Chos Malal FTB to comprehend the structural style that characterize this area located between the Cordillera del Viento and the Tromen volcano. Four balanced structural cross-section were interpreted based on detailed field mapping, information of seismic lines and well logs registers. In order to understand the deformation in the area, all the structures outcropping were mapped, considering the different orders of folding; the structures of first order that involved the basement and the minor order structures developed in the sedimentary basin fill.