Seismostratigraphic and structural setting of the Malvinas Basin and its southern margin (Tierra del fuego Atlantic offshore)
Tassone, Alejandro (Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales)
Lodolo, Emanuele (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale)
Menichetti, Marco (Università di Urbino. Istituto di Scienze della Terra)
Yagupsky, Daniel Leonardo (Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales)
Caffau, Mario (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale)
Vilas, Juan Francisco Antonio (Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales)
Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina). INGEODAV (Instituto de Geofísica "Daniel A. Valencio")

Date:	2008
Abstract:	New multichannel seismic reflection profiles acquired off the Tierra del Fuego Atlantic margin, from the southern part of the Malvinas foreland basin to the inner sector of the Magallanes fold and thrust belt, combined with available commercial profiles and exploration wells, allowed to outline the sedimentary architecture of the foreland basin and the structure of its deformed southern margin. Five major unconformities were differentiated within the sedimentary fill of the southern Malvinas basin, which neighbours the offshore extension of the Magallanes basin in Tierra del Fuego. The unconformity-bounded units record the corresponding major evolutionary tectonostratigraphic phases of the southern part of the Malvinas basin, and the development of the Magallanes fold-and thrust belt during Mesozoic and Cenozoic times: Unit 1 - Pre-Jurassic basement; Unit 2 - Rift phase (Middle - Upper Jurassic); Unit 3 - Sag phase (Lower - Upper Cretaceous); Unit 4 - Foredeep transitional phase (Upper Cretaceous - Middle Eocene); Unit 5 - Foreland phase (Middle Eocene - Pleistocene). The southern edge of the Malvinas basin corresponds to the imbricate basement wedges of the Fuegian Cordillera, which shows a thick-skin structural style developed as a consequence of the Middle Tertiary Andean compressional tectonic phase. Large folds, with low angle NE-verging thrusts propagated the shortening basin-ward at shallow structural levels. These structures are superimposed by an array of left-lateral strike-slip lineaments pertaining to the EW trending Magallanes-Fagnano fault system. In the Tierra del Fuego region these structures represent the western segment of the South America - Scotia plate boundary. Several Neogene pull-apart basins were formed along the principal deformation zone in correspondence of step-overs and releasing bends. These basins show an evident asymmetry in the sedimentary architecture, and are bounded by sub-vertical faults that in some cases reach the sea-floor. Other transtensional features were also recognized in the inner sector of the fold-and-thrust belt together with the formation of restricted pull-apart basins.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Tierra del Fuego ; Atlantic margin ; Malvinas basin ; Magallanes fold-and-thrust belt ; Tectonic evolution ; Seismostratigraphy ; Multichannel seismic data
Published in:	Geologica acta, Vol. 6, Núm. 1 (Març 2008) , p. 55-67, ISSN 1696-5728

Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/83444
Adreça alternativa: https://revistes.ub.edu/index.php/GEOACTA/article/view/105.000000241
DOI: 10.1344/105.000000241

13 p, 2.6 MB

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