Journal cover Journal topic
Solid Earth An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 2.380 IF 2.380
  • IF 5-year value: 3.147 IF 5-year
    3.147
  • CiteScore value: 3.06 CiteScore
    3.06
  • SNIP value: 1.335 SNIP 1.335
  • IPP value: 2.81 IPP 2.81
  • SJR value: 0.779 SJR 0.779
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 32 Scimago H
    index 32
  • h5-index value: 31 h5-index 31
Discussion papers
https://doi.org/10.5194/se-2019-99
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/se-2019-99
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 11 Jun 2019

Research article | 11 Jun 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Solid Earth (SE).

Determining the Plio-Quaternary uplift of the southern French massif-Central; a new insights for intraplate orogen dynamics

Oswald Malcles1, Philippe Vernant1, Jean Chéry1, Pierre Camps1, Gaël Cazes2,3, Jean-François Ritz1, and David Fink3 Oswald Malcles et al.
  • 1Geosciences Montpellier, CNRS-University of Montpellier, Montpellier, France
  • 2SEES, University of Wollongong, Wollongong, Australia
  • 3Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia

Abstract. The evolution of intra-plate orogens is still poorly understood. Yet, this is of major importance for understanding the Earth and plate dynamic, as well as the link between surface and deep geodynamic processes. The French Massif Central is an intraplate orogen with a mean elevation of 1000 m, with the highest peak elevations ranging from 1500 m to 1885 m. However, active deformation of the region is still debated due to scarce evidence either from geomorphological or geophysical (i.e. geodesy and seismology) data. Because the Cévennes margin allows the use of karst sediments geochronology and morphometrical analysis, we study the vertical displacements of that region: the southern part of the French Massif-Central. Geochronology and morphometrical results, helped with lithospheric-scale numerical modelling, allow, then, a better understanding of this intraplate-orogen evolution and dynamic.

Using the ability of the karst to durably record morphological evolution, we first quantify the incision rates. We then investigate tilting of geomorphological benchmarks by means of a high-resolution DEM. We finally use the newly quantified incision rates to constrain numerical models and compare the results with the geomorphometric study.

We show that absolute burial age (10Be/26Al on quartz cobbles) and the paleomagnetic analysis of karstic clay deposits for multiple cave system over a large elevation range correlate consistently. This correlation indicates a regional incision rate of 83.4 +17.3/−5.4 m Ma−1 during the last ca 4 Myrs (Plio-Quaternary). Moreover, we point out through the analysis of 55 morphological benchmarks that the studied region has undergone a regional southward tilting. This tilting is expected as being due to a differential vertical motion between the north and southern part of the studied area.

Numerical models show that erosion-induced isostatic rebound can explain up to two-thirds of the regional uplift deduced from dating technics and are consistent with the southward tilting obtain from morphological analysis. We presume that the remaining part is related to dynamic topography or thermal isostasy due to the Massif Central plio-quaternary magmatism.

Oswald Malcles et al.
Interactive discussion
Status: open (until 07 Aug 2019)
Status: open (until 07 Aug 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Oswald Malcles et al.
Oswald Malcles et al.
Viewed  
Total article views: 205 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
154 50 1 205 0 0
  • HTML: 154
  • PDF: 50
  • XML: 1
  • Total: 205
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 11 Jun 2019)
Cumulative views and downloads (calculated since 11 Jun 2019)
Viewed (geographical distribution)  
Total article views: 160 (including HTML, PDF, and XML) Thereof 156 with geography defined and 4 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 19 Jul 2019
Publications Copernicus
Download
Short summary
We aim at a better understanding of the challenging areas that are the intra-plate regions using one example: the southern French Massif-Central and its numerous 100s meter deep valleys. We there apply a multi-disciplinary approach using geomorphology, geochronology and numerical modelling. Our dating results show that the canyons incision are part of the Plio-Quaternary evolution with incision rate of ~ 80m/Ma. We propose then that this incision is possible due to an active regional uplift.
We aim at a better understanding of the challenging areas that are the intra-plate regions using...
Citation