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Tectonic response of the central Chilean margin (35-38 degrees S) to the collision and subduction of heterogeneous oceanic crust: a thermochronological study

Spikings, R.; Dungan, M.; Foeken, J.; Carter, A.; Page, Laurence LU and Stuart, F. (2008) In Journal of the Geological Society 165(5). p.941-953
Abstract
Along-strike geological segmentation in the Andean chain has been recognized at various scales and is Usually attributed to changes in plate motion vectors, as well as the upper-plate expression of differing subducted slab age, strength and composition. We present new multi-phase Ar-40/Ar-39, apatite fission-track and zircon and apatite (U-Th)/He data from a north-south-oriented traverse between 35 and 38 degrees S along the Principal Andean Cordillera of Chile that reveal (1) rapid cooling at 18 and 15 Ma, which can be attributed to both thermal relaxation following magmatic intrusion and regional-scale exhumation, and (2) along-strike differences in the extent of exhumation since 7.5 Ma that may be a consequence of the subduction of the... (More)
Along-strike geological segmentation in the Andean chain has been recognized at various scales and is Usually attributed to changes in plate motion vectors, as well as the upper-plate expression of differing subducted slab age, strength and composition. We present new multi-phase Ar-40/Ar-39, apatite fission-track and zircon and apatite (U-Th)/He data from a north-south-oriented traverse between 35 and 38 degrees S along the Principal Andean Cordillera of Chile that reveal (1) rapid cooling at 18 and 15 Ma, which can be attributed to both thermal relaxation following magmatic intrusion and regional-scale exhumation, and (2) along-strike differences in the extent of exhumation since 7.5 Ma that may be a consequence of the subduction of the loan Fernandez Ridge above the flat-slab segment at 32 degrees, since 10 Ma. A comparison of the response of the South American Plate to the collision of the Carnegie, Nazca and Juan Fernandez ridges suggests that slab flattening is not the dominant driving force that exhumes the upper plate in these settings. Rather, the extent of exhumation is controlled by pre-existing structural weaknesses, the time duration of the dynamically supported topography, and climate. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the Geological Society
volume
165
issue
5
pages
941 - 953
publisher
The Geological Society Publishing House
external identifiers
  • wos:000258901600007
  • scopus:51949109516
ISSN
2041-479X
DOI
10.1144/0016-76492007-115
language
English
LU publication?
yes
id
644de552-e1f3-47bd-b39a-516c61a4187b (old id 1247228)
date added to LUP
2008-11-11 15:00:33
date last changed
2017-09-17 04:28:51
@article{644de552-e1f3-47bd-b39a-516c61a4187b,
  abstract     = {Along-strike geological segmentation in the Andean chain has been recognized at various scales and is Usually attributed to changes in plate motion vectors, as well as the upper-plate expression of differing subducted slab age, strength and composition. We present new multi-phase Ar-40/Ar-39, apatite fission-track and zircon and apatite (U-Th)/He data from a north-south-oriented traverse between 35 and 38 degrees S along the Principal Andean Cordillera of Chile that reveal (1) rapid cooling at 18 and 15 Ma, which can be attributed to both thermal relaxation following magmatic intrusion and regional-scale exhumation, and (2) along-strike differences in the extent of exhumation since 7.5 Ma that may be a consequence of the subduction of the loan Fernandez Ridge above the flat-slab segment at 32 degrees, since 10 Ma. A comparison of the response of the South American Plate to the collision of the Carnegie, Nazca and Juan Fernandez ridges suggests that slab flattening is not the dominant driving force that exhumes the upper plate in these settings. Rather, the extent of exhumation is controlled by pre-existing structural weaknesses, the time duration of the dynamically supported topography, and climate.},
  author       = {Spikings, R. and Dungan, M. and Foeken, J. and Carter, A. and Page, Laurence and Stuart, F.},
  issn         = {2041-479X},
  language     = {eng},
  number       = {5},
  pages        = {941--953},
  publisher    = {The Geological Society Publishing House},
  series       = {Journal of the Geological Society},
  title        = {Tectonic response of the central Chilean margin (35-38 degrees S) to the collision and subduction of heterogeneous oceanic crust: a thermochronological study},
  url          = {http://dx.doi.org/10.1144/0016-76492007-115},
  volume       = {165},
  year         = {2008},
}