Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Argentine → Morphotectonic characterization of Otumpa hills (Gran Chaco, Santiago del Estero and Chaco) : Influences on drainage control

Universidad de Buenos Aires (2012)

Morphotectonic characterization of Otumpa hills (Gran Chaco, Santiago del Estero and Chaco) : Influences on drainage control

Peri, Verónica Gisel

Titre : Morphotectonic characterization of Otumpa hills (Gran Chaco, Santiago del Estero and Chaco) : Influences on drainage control

Caracterización morfotectónica de las Lomadas de Otumpa (Gran Chaco, Santiago del Estero y Chaco) : Influencias en el control del drenaje

Auteur : Peri, Verónica Gisel

Université de soutenance : Universidad de Buenos Aires

Grade : Doctor 2012

Résumé
A multi-scale morphotectonic characterization of Otumpa hills (Gran Chaco Argentino) was made linked to a dynamic analysis of the design and evolution of the drainage network. The morphotectonic deep characterization was carried out by a magnetotelluric survey in a sublatitudinal transect at 27 ° south latitude, that show the electrical structure at crust-mantle scale and led identified the sedimentary basins at shallow scale. Furthermore, an analysis of deep seismicity in the region was made (500-600 km), to complement the deep characteristics. The morphotectonic intermediate characterization was based on seismic reflection, residual gravity anomalies, lithology logs from oil drilling and global data field stress, which outlined a structural model. The morphotectonic shallow characterization was based on two audiomagnetotelluric and a geoelectrical profiles, which identified electrical horizons that were correlated to lithological units recognized in boreholes. Morphotectonic surface characterization based on the identification of geomorphological units and calculation of parameter geomorphometrics, show abnormalities of the relief and drainage manifest mainly on the floodplain and old channels of Salado North river. Also were explored the rocky outcrops of the eastern Otumpa hills which finally were correlated to the Upper Jurassic-Lower Cretaceous aeolian deposits or Misiones formation. Evident and important events of silicification and weathering were observed on it. The Otumpa hills are a relict gondwanan morphostructure with Mesozoic and Cenozoic reactivation influential in the development of patterns of old and current drainage network. It is important in the determination of possible western boundary of the Guarani Aquifer System and the contribution of applied stone materials for construction

Mots clés : LOMADAS DE OTUMPA ; GRAN CHACO ARGENTINO ; CARACTERIZACION MORFOTECTONICA ; DRENAJE ; MAGNETOTELURICA ; FORMACION MISIONES ; OTUMPA HILLS ; GRAN CHACO ARGENTINO ; MORPHOTECTONIC CHARACTERIZATION ; DRAINAGE ; MAGNETOTELLURICS ; MISIONES FORMATION

Présentation (Biblioteca Digital)

Version intégrale

Page publiée le 9 octobre 2017, mise à jour le 13 février 2020