INVESTIGADORES
PINOTTI Lucio Pedro
artículos
Título:
Tectono-magnatic response to convergence major changes in the north patagonian suprasubductionsystem; the paleogene subduction-transcurrent plate margin transition.
Autor/es:
EUGENIO ARAGÓN, FERNANDO D`ERAMO, , ANTONIO CASTRO, LUCIO PINOTTI, DANIELE BRUNELLI, GIORGIO RIVALENTI, RICARDO VARELA, WIM SPAKMAN, MANUEL DEMARTIS, CLAUDIA E. CAVAROZZI, YOLANDA E. AGUILERA, MAURIZIO MAZZUCCHELLI, ALEJANDRO RIBOT
Revista:
TECTONOPHYSICS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 509 p. 218 - 237
ISSN:
0040-1951
Resumen:
The southern and central Andes reflect significant along-strike differences of tectonic activity, including
shortening, alternating flat-to-normal subduction styles and magmatism. In northern Patagonia, the
subduction/supra-subduction system, fore arc, arc and back arc basins developed in an extensional setting
during the Paleogene. This was accompanied by landward migration of calc-alkalic magmatism which
changed to synextensional bimodal volcanism of rhyolitic ignimbrites and interbedded tholeiitic and alkalic
basalts. These Paleogene events occurred during a time when the Farallon?Aluk active ridge reached the
South American plate, and the Farallon plate subduction was interrupted. They represent a new tectonic
regime, characterized by a transcurrent plate margin. The presence in the back arc of a rigid lithospheric block
of 100,000 km2 represented by the North Patagonian Massif focused the rotation of the coastal blocks. This
resulted in the development of two Paleogene extensional regions to the north and south, respectively, of the
Massif and replaced the former back arc. Plate rearrangement caused by the inauguration of the Nazca plate
and its regime of orthogonal subduction at the beginning of the Miocene, re-established typical calc-alkaline
arc magmatism at the former upper Cretaceous arc locus. Present seismic activity in the subducted plate and
tomographic modeling of p-wave velocity anomalies in the upper mantle also suggest the presence of a
subduction gap that lasted for most of the Paleogene in northern Patagonia.flect significant along-strike differences of tectonic activity, including
shortening, alternating flat-to-normal subduction styles and magmatism. In northern Patagonia, the
subduction/supra-subduction system, fore arc, arc and back arc basins developed in an extensional setting
during the Paleogene. This was accompanied by landward migration of calc-alkalic magmatism which
changed to synextensional bimodal volcanism of rhyolitic ignimbrites and interbedded tholeiitic and alkalic
basalts. These Paleogene events occurred during a time when the Farallon?Aluk active ridge reached the
South American plate, and the Farallon plate subduction was interrupted. They represent a new tectonic
regime, characterized by a transcurrent plate margin. The presence in the back arc of a rigid lithospheric block
of 100,000 km2 represented by the North Patagonian Massif focused the rotation of the coastal blocks. This
resulted in the development of two Paleogene extensional regions to the north and south, respectively, of the
Massif and replaced the former back arc. Plate rearrangement caused by the inauguration of the Nazca plate
and its regime of orthogonal subduction at the beginning of the Miocene, re-established typical calc-alkaline
arc magmatism at the former upper Cretaceous arc locus. Present seismic activity in the subducted plate and
tomographic modeling of p-wave velocity anomalies in the upper mantle also suggest the presence of a
subduction gap that lasted for most of the Paleogene in northern Patagonia.flat-to-normal subduction styles and magmatism. In northern Patagonia, the
subduction/supra-subduction system, fore arc, arc and back arc basins developed in an extensional setting
during the Paleogene. This was accompanied by landward migration of calc-alkalic magmatism which
changed to synextensional bimodal volcanism of rhyolitic ignimbrites and interbedded tholeiitic and alkalic
basalts. These Paleogene events occurred during a time when the Farallon?Aluk active ridge reached the
South American plate, and the Farallon plate subduction was interrupted. They represent a new tectonic
regime, characterized by a transcurrent plate margin. The presence in the back arc of a rigid lithospheric block
of 100,000 km2 represented by the North Patagonian Massif focused the rotation of the coastal blocks. This
resulted in the development of two Paleogene extensional regions to the north and south, respectively, of the
Massif and replaced the former back arc. Plate rearrangement caused by the inauguration of the Nazca plate
and its regime of orthogonal subduction at the beginning of the Miocene, re-established typical calc-alkaline
arc magmatism at the former upper Cretaceous arc locus. Present seismic activity in the subducted plate and
tomographic modeling of p-wave velocity anomalies in the upper mantle also suggest the presence of a
subduction gap that lasted for most of the Paleogene in northern Patagonia.?Aluk active ridge reached the
South American plate, and the Farallon plate subduction was interrupted. They represent a new tectonic
regime, characterized by a transcurrent plate margin. The presence in the back arc of a rigid lithospheric block
of 100,000 km2 represented by the North Patagonian Massif focused the rotation of the coastal blocks. This
resulted in the development of two Paleogene extensional regions to the north and south, respectively, of the
Massif and replaced the former back arc. Plate rearrangement caused by the inauguration of the Nazca plate
and its regime of orthogonal subduction at the beginning of the Miocene, re-established typical calc-alkaline
arc magmatism at the former upper Cretaceous arc locus. Present seismic activity in the subducted plate and
tomographic modeling of p-wave velocity anomalies in the upper mantle also suggest the presence of a
subduction gap that lasted for most of the Paleogene in northern Patagonia.2 represented by the North Patagonian Massif focused the rotation of the coastal blocks. This
resulted in the development of two Paleogene extensional regions to the north and south, respectively, of the
Massif and replaced the former back arc. Plate rearrangement caused by the inauguration of the Nazca plate
and its regime of orthogonal subduction at the beginning of the Miocene, re-established typical calc-alkaline
arc magmatism at the former upper Cretaceous arc locus. Present seismic activity in the subducted plate and
tomographic modeling of p-wave velocity anomalies in the upper mantle also suggest the presence of a
subduction gap that lasted for most of the Paleogene in northern Patagonia.