Neogene epeirogeny of Iberia
File(s)
Accepted version
Author(s)
Conway-Jones, Benedict W
Roberts, Gareth G
Fichtner, Andreas
Hoggard, Mark
Type
Journal Article
Abstract
The origin of Iberia's topography is examined by combining gravity, magmatic, topographic and seismological observations with geomorphic considerations. We have four principal results. First, highest coherence between free‐air gravity and topography is at wavelengths ≲250 km where admittance indicates that elastic thickness of Iberia's plate is 20 ± 3 km. These results imply that flexural and sub‐plate support of Iberian topography could be expressed at wavelengths of O(100) km. Secondly, P‐to‐S receiver functions and simple isostatic calculations indicate that whilst crustal thickness variations and flexural loading (e.g. as a result of plate shortening) partially explain the elevation of Pyrenean, Betics, Cantabrian, Spanish Central System and Iberian Chain topography, they fail to explain the elevation of large parts of Iberia. Thirdly, a new full waveform shear wave tomographic model and velocity to temperature conversions suggest that the asthenosphere beneath Iberia is anomalously slow and has excess temperatures of up to 162 ± 14°C. Simple isostatic calculations indicate asthenospheric support of topography of up to 1 km. Neogene‐Recent (∼23–0 Ma) extrusive magmatism (e.g. Calatrava, Catalan) sit atop many of the slow shear wave velocity anomalies. Finally, biostratigraphic data, combined with inversion of 3217 river profiles, show that most of Iberia's topography grew during the last ∼30 Ma at rates of up to 0.3 mm yr−1. Best‐fitting theoretical rivers have a low residual rms misfit (=0.96) and calculated uplift is consistent with an independent inventory of stratigraphic and biostratigraphic observations. We suggest that Neogene‐Recent growth of most of central Iberia's topography was a result of asthenospheric support.
Date Issued
2019-02
Date Acceptance
2019-01-16
Citation
Geochemistry, Geophysics, Geosystems, 2019, 20 (2), pp.1138-1163
ISSN
1525-2027
Publisher
American Geophysical Union (AGU)
Start Page
1138
End Page
1163
Journal / Book Title
Geochemistry, Geophysics, Geosystems
Volume
20
Issue
2
Copyright Statement
© 2019 American Geophysical Union. An edited version of this paper was published by AGU. Conway‐Jones, B.W., G.G Roberts, A. Fichtner, and M.J. Hoggard. (2019), Neogene Epeirogeny of Iberia, Geochem. Geophys. Geosyst., 20. DOI: 10.1029/2018GC007899. To view the published open abstract, go to: https://dx.doi.org/10.1029/2018gc007899
Identifier
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GC007899
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
Iberia
uplift
mantle
dynamic support
inversion
full waveform tomography
FISSION-TRACK THERMOCHRONOLOGY
PAMPLONA BASIN NAVARRE
BETIC CORDILLERA
VOLCANIC PROVINCE
ALPUJARRIDE COMPLEX
TECTONIC EVOLUTION
FLUVIAL INCISION
CENTRAL PYRENEES
MARINE TERRACES
STRUCTURAL DATA
04 Earth Sciences
02 Physical Sciences
Geochemistry & Geophysics
Publication Status
Published
Date Publish Online
2019-01-18