Antarctic Peninsula path since breakup: review and implications for James Ross Basin development Marta E. Ghidella Instituto Ant

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Antarctic Peninsula path since breakup review
and implications for James Ross Basin
developmentMarta E. GhidellaInstituto
Antártico Argentino
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Introduction

• Examine of the Antactic Peninsula path for four
  tectonic models

1. Ghidella et al (2002)
2. Lawver et al (1999)
3. Livermore Nankivell Eagles (1996, 1997, 2000)
4. Jokat et al (2003)

• Examine the relationship of the AP path with
  James Ross Basin development

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James Ross Basin
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Reconstructions

• We are going to show reconstructions for the SAM
  movement, ANT kept fixed
• We are not including the reconstruction of the
  Scotia plate
• The plots include synthetic isochrons, calculated
  from rotated C34 picks.
• The path of one point of the tip of the Antarctic
  Peninsula will be displayed for each epoch

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Ghidella et al
Reconstructions begin ... Next
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Ghi - 160 - SAM fixed
Ghi 160 - SAM fixed
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Ghi-147-SAM fixed
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Ghi 131 - SAM fixed
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Ghi 118 - SAM fixed
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Ghi 90 - SAM fixed
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Ghi 83 - SAM fixed
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Ghi 66 - SAM fixed
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Ghi 33 - SAM fixed
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Ghi - 26 - SAM fixed
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Ghi 0 SAM fixed
back
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Lawver et al
Reconstructions continue ... Next
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Law 160 SAM fixed
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Law 147 SAM fixed
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Law 131 SAM fixed
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Law 118 SAM fixed
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Law 90 SAM fixed
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Law 83 SAM fixed
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Law 66 SAM fixed
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Law 33 SAM fixed
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Law 26 SAM fixed
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Law 0 SAM fixed
back
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Jokat et al
Reconstructions continue ... Next
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Jo 159 SAM fixed
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Jo 147 SAM fixed
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Jo 131 SAM fixed
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Jo 118 SAM fixed
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Jo 90 SAM fixed
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Jo 83 SAM fixed
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Jo 66 SAM fixed
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Jo 33 SAM fixed
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Jo 26 SAM fixed
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Jo 0 SAM fixed
back
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Livermore Nankivell - Eagles
Reconstructions continue ... Next
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Liv 165 SAM fixed
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Liv 150 SAM fixed
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Liv 132 SAM fixed
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Liv 119 SAM fixed
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Liv 93 SAM fixed
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Liv 83 SAM fixed
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Liv 66 SAM fixed
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Liv 33 SAM fixed
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Liv 26 SAM fixed
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Liv 0 SAM fixed
back
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End of reconstructions
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All paths at present
Lawver
Ghidella
Jokat
Livermore
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Reconstruction of the magnetic anomaly field in
the Scotia Sea at 66.6 Ma by Graeme Eagles
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Our plot of 66.5 Ma with ANT fixed
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Comparison

• Some features of James Ross Basin evolution from
  del Valle et al (1995)
• Inferences from common features of the AP path in
  the four reconstructions

del Valle, R.A., Lirio, J.M., Rinaldi, C.A.,
1993 Sedimentación y tectónica en la cuenca de
Larsen, Antártida. Proc. of the XII Congreso
Geológico Argentino, vol. III, 135-143.
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AP velocity
James Ross Basin subsidence and tectonic episodes
South Atlantic opens
Powell Basin opens
Rotation near AP tip
AP overrides oceanic crust
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Summary
The four models differ before the opening of the
South Atlantic (132 Ma) Common features
afterwards 1) Rotation near AP tip 120 90
Ma ... (30 Ma !!!!) JRB slow rate of
sedimentation episodes of compressive
wrench tectonics 2) AP overriding SAM-ANT oceanic
crust -gt 80 34 Ma JRB increased
sedimentation rate during 15 Ma episodes
of compressive wrench tectonics Perhaps the
compressive tectonics is more important in 2 ?
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end
Thank you for your attention ...