Kinematics of early paleozoic ductile deformation in the basement of NW Argentina

Preliminary results are presented based on the analysis of kinematics and finite strain associated with pre-Carboniferous tectonometamorphic events recorded in various basement blocks of NW Argentina (Sierras Pampeanas, southern Puna). It would appear that various granitoids and their metamorphic co...

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Publicado: 1994
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v7_n3-4_p301_LeCorre
http://hdl.handle.net/20.500.12110/paper_08959811_v7_n3-4_p301_LeCorre
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spelling paper:paper_08959811_v7_n3-4_p301_LeCorre2023-06-08T15:49:01Z Kinematics of early paleozoic ductile deformation in the basement of NW Argentina basement deformation foliation Palaeozoic tectonics thrusting Argentina, Puna Argentina, Sierra Pampeanas Preliminary results are presented based on the analysis of kinematics and finite strain associated with pre-Carboniferous tectonometamorphic events recorded in various basement blocks of NW Argentina (Sierras Pampeanas, southern Puna). It would appear that various granitoids and their metamorphic country rocks have been affected by the same deformational phase: a N-S trending foliation, sometimes gently dipping, associated with a pronounced stretching lineation generally showing steep pitchs. Kinematic criteria indicate that movements were mostly vertical or involved thrusting of the eastern block over the western block. In some rare cases, the movement picture is reversed, with overthrusting of the western block onto the eastern block. Andean tectonic activity can cause local complications to these interpretations by introducing tilting or rotation of the blocks. However, on the basis of present study, it is possible to establish that tectonic events affecting the pre-Carboniferous basement involved thrusting with minor wrenching. Two main structural domains can be recognized: in the south, the Sierras Pampeanas, characterized by westward-directed thrusting; in the north, near the edge of the Puna region, more variable kinematics are associated with thrusting towards the east and also towards the west. In this way, it is possible to confirm the existence of an E-W compressive regime during pre-Carboniferous times across the entire western border of the Pre-Andean basement. This compression contributed to crustal thickening and the bringing together of previously widely separated blocks. The systematic observation of geometric and kinematic criteria associated with ductile deformation should enable us to place better constraints on geodynamic interpretations of the Pre-Andean domain. © 1994. 1994 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v7_n3-4_p301_LeCorre http://hdl.handle.net/20.500.12110/paper_08959811_v7_n3-4_p301_LeCorre
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic basement
deformation
foliation
Palaeozoic
tectonics
thrusting
Argentina, Puna
Argentina, Sierra Pampeanas
spellingShingle basement
deformation
foliation
Palaeozoic
tectonics
thrusting
Argentina, Puna
Argentina, Sierra Pampeanas
Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
topic_facet basement
deformation
foliation
Palaeozoic
tectonics
thrusting
Argentina, Puna
Argentina, Sierra Pampeanas
description Preliminary results are presented based on the analysis of kinematics and finite strain associated with pre-Carboniferous tectonometamorphic events recorded in various basement blocks of NW Argentina (Sierras Pampeanas, southern Puna). It would appear that various granitoids and their metamorphic country rocks have been affected by the same deformational phase: a N-S trending foliation, sometimes gently dipping, associated with a pronounced stretching lineation generally showing steep pitchs. Kinematic criteria indicate that movements were mostly vertical or involved thrusting of the eastern block over the western block. In some rare cases, the movement picture is reversed, with overthrusting of the western block onto the eastern block. Andean tectonic activity can cause local complications to these interpretations by introducing tilting or rotation of the blocks. However, on the basis of present study, it is possible to establish that tectonic events affecting the pre-Carboniferous basement involved thrusting with minor wrenching. Two main structural domains can be recognized: in the south, the Sierras Pampeanas, characterized by westward-directed thrusting; in the north, near the edge of the Puna region, more variable kinematics are associated with thrusting towards the east and also towards the west. In this way, it is possible to confirm the existence of an E-W compressive regime during pre-Carboniferous times across the entire western border of the Pre-Andean basement. This compression contributed to crustal thickening and the bringing together of previously widely separated blocks. The systematic observation of geometric and kinematic criteria associated with ductile deformation should enable us to place better constraints on geodynamic interpretations of the Pre-Andean domain. © 1994.
title Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
title_short Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
title_full Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
title_fullStr Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
title_full_unstemmed Kinematics of early paleozoic ductile deformation in the basement of NW Argentina
title_sort kinematics of early paleozoic ductile deformation in the basement of nw argentina
publishDate 1994
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v7_n3-4_p301_LeCorre
http://hdl.handle.net/20.500.12110/paper_08959811_v7_n3-4_p301_LeCorre
_version_ 1768542182958956544