Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin
The southern Chilean convergent margin, between 50° and 57° S, is shaped by the interaction of the three main plates: Antarctic, South America and Scotia. North of 53° S, the convergence between Antarctic and South America plates is close to orthogonal to the continental margin strike. Here, the def...
Published in: | Tectonophysics |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2007
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/2808/ https://oceanrep.geomar.de/id/eprint/2808/1/Loreto.pdf https://doi.org/10.1016/j.tecto.2006.09.016 |
id |
ftoceanrep:oai:oceanrep.geomar.de:2808 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:2808 2024-09-30T14:25:15+00:00 Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin Loreto, Maria Filomena Tinivella, Umberta Ranero, César R. 2007 text https://oceanrep.geomar.de/id/eprint/2808/ https://oceanrep.geomar.de/id/eprint/2808/1/Loreto.pdf https://doi.org/10.1016/j.tecto.2006.09.016 en eng Elsevier https://oceanrep.geomar.de/id/eprint/2808/1/Loreto.pdf Loreto, M. F., Tinivella, U. and Ranero, C. R. (2007) Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin. Tectonophysics, 429 (3/4). pp. 183-200. DOI 10.1016/j.tecto.2006.09.016 <https://doi.org/10.1016/j.tecto.2006.09.016>. doi:10.1016/j.tecto.2006.09.016 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2007 ftoceanrep https://doi.org/10.1016/j.tecto.2006.09.016 2024-09-04T05:04:40Z The southern Chilean convergent margin, between 50° and 57° S, is shaped by the interaction of the three main plates: Antarctic, South America and Scotia. North of 53° S, the convergence between Antarctic and South America plates is close to orthogonal to the continental margin strike. Here, the deformational style of the accretionary prism is mainly characterized by seaward-verging thrusts and locally by normal faults and fractures, a very limited lateral extension of prism, a very shallow dip (∼ 6°) décollement, and subduction of a thick and relatively undeformed trench sedimentary sequence. South of 53° S, convergence is oblique to the margin, locally, the trench sediments are proto-deformed by double vergence thrusting and the front of the prism grows through landward-verging thrusting. The décollement is sub-horizontal and deep, involving most of the sediment over the oceanic crust in the accretionary process, building a comparatively wide and thicker prism. A Bottom Simulating Reflector is present across the whole prism to the abyssal plan, suggesting the presence of gas in the sediments. The analysis of P- and S-wave velocity reflectivity sections, derived by amplitude versus offset technique (AVO), detailed velocity information and the velocity-derived sediment porosity have been integrated with the structural analysis of the accretionary prism of two selected pre-stack depth migrated seismic lines, aiming to explain the relation between fluid circulation and tectonics. Accretion along double vergence thrust faults may be associated with the presence of overpressured fluid, which decreases the effective shear stress coefficient along the main décollement and within the sediments, and modify the rheolgical properties of rocks. The presence of an adequate drainage network, represented by interconnected faults and fractures affecting the entire sedimentary sequence, can favour the escape of pore fluid toward the sea bottom, while, less permeable and not faulted sediments can favour fluid accumulations. ... Article in Journal/Newspaper Antarc* Antarctic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Tectonophysics 429 3-4 183 200 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The southern Chilean convergent margin, between 50° and 57° S, is shaped by the interaction of the three main plates: Antarctic, South America and Scotia. North of 53° S, the convergence between Antarctic and South America plates is close to orthogonal to the continental margin strike. Here, the deformational style of the accretionary prism is mainly characterized by seaward-verging thrusts and locally by normal faults and fractures, a very limited lateral extension of prism, a very shallow dip (∼ 6°) décollement, and subduction of a thick and relatively undeformed trench sedimentary sequence. South of 53° S, convergence is oblique to the margin, locally, the trench sediments are proto-deformed by double vergence thrusting and the front of the prism grows through landward-verging thrusting. The décollement is sub-horizontal and deep, involving most of the sediment over the oceanic crust in the accretionary process, building a comparatively wide and thicker prism. A Bottom Simulating Reflector is present across the whole prism to the abyssal plan, suggesting the presence of gas in the sediments. The analysis of P- and S-wave velocity reflectivity sections, derived by amplitude versus offset technique (AVO), detailed velocity information and the velocity-derived sediment porosity have been integrated with the structural analysis of the accretionary prism of two selected pre-stack depth migrated seismic lines, aiming to explain the relation between fluid circulation and tectonics. Accretion along double vergence thrust faults may be associated with the presence of overpressured fluid, which decreases the effective shear stress coefficient along the main décollement and within the sediments, and modify the rheolgical properties of rocks. The presence of an adequate drainage network, represented by interconnected faults and fractures affecting the entire sedimentary sequence, can favour the escape of pore fluid toward the sea bottom, while, less permeable and not faulted sediments can favour fluid accumulations. ... |
format |
Article in Journal/Newspaper |
author |
Loreto, Maria Filomena Tinivella, Umberta Ranero, César R. |
spellingShingle |
Loreto, Maria Filomena Tinivella, Umberta Ranero, César R. Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
author_facet |
Loreto, Maria Filomena Tinivella, Umberta Ranero, César R. |
author_sort |
Loreto, Maria Filomena |
title |
Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
title_short |
Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
title_full |
Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
title_fullStr |
Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
title_full_unstemmed |
Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin |
title_sort |
evidence for fluid circulation, overpressure and tectonic style along the southern chilean margin |
publisher |
Elsevier |
publishDate |
2007 |
url |
https://oceanrep.geomar.de/id/eprint/2808/ https://oceanrep.geomar.de/id/eprint/2808/1/Loreto.pdf https://doi.org/10.1016/j.tecto.2006.09.016 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
https://oceanrep.geomar.de/id/eprint/2808/1/Loreto.pdf Loreto, M. F., Tinivella, U. and Ranero, C. R. (2007) Evidence for fluid circulation, overpressure and tectonic style along the southern Chilean margin. Tectonophysics, 429 (3/4). pp. 183-200. DOI 10.1016/j.tecto.2006.09.016 <https://doi.org/10.1016/j.tecto.2006.09.016>. doi:10.1016/j.tecto.2006.09.016 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.tecto.2006.09.016 |
container_title |
Tectonophysics |
container_volume |
429 |
container_issue |
3-4 |
container_start_page |
183 |
op_container_end_page |
200 |
_version_ |
1811644060230746112 |