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| Titel |
Lateral Strength Variations in Iberia and their Influence on Intra-plate Mountain Building: Inferences from Analogue Modelling |
| VerfasserIn |
Javier Fernández-Lozano, Dimitrios Sokoutis, Ernst Willingshofer, Alfonso Muñoz-Martín, Gerardo De Vicente, Sierd Cloetingh  |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034695
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| Zusammenfassung |
| Analogue modelling alludes to the presence of lithosphere scale folds in Iberia as a result of
large-scale convergence during Oligocene-Miocene times between the Iberian and Europe
Plates. Different tectono-thermal events affected the Microplate since late Paleozoic and
resulted in lateral strength variations of the Iberian lithosphere. An old and cold
lithosphere, Variscan in age, can be found in the western most part of Iberia whereas a
relative weak and hot Mesozoic lithosphere affected by episodes of rifting and basin
inversion during Mesozoic-Tertiary times covers the area of the Iberian Chain.
Our study aims at deciphering whether deformation and topography evolution in
Iberia are related to lateral strength variations and/or the inherited structural grain
stemming from Variscan deformation. Interpretation of the modelling results has been
aided through the analysis of gravity anomalies of the physical experiments and
by particle tracing techniques (PIV). We also integrate the total strength of the
lithosphere to gain insights into the effects of rheological variations related to local
thrusting or initial strength variations along the Iberian lithosphere. The newly
implemented tools also may help to provide useful information about the mechanism of
folding affecting the lithospheres characterized by different strengths under horizontal
compression. Our results emphasise the control of folding on the wavelengths of the
Bouguer Gravity anomalies and crustal thickness variations. Thickening of the ductile
layers occurred at the sites of broad synforms where topography developed and
where gravity lows are predicted. Unlike the strong lithosphere, which responded to
shortening by folding, the weak lithosphere is mainly deformed by thickening. These
differences become evident from the PIV analysis and the obtained crustal thickness
and strength maps from the models. The results are consistent with geological and
geophysical observations in Iberia where lateral changes in strength of the lithosphere, are
thought to have resulted in thickness variations during tectonic inversion affecting the
eastern part of Iberia (Iberian Chain), while the western part remains more stable. |
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