Orogenic growth in the atlas mountains of SW Marocco - Insights from low-temperature thermochronometry and in situ cosmogenic dating
| Responsable du projet |
Angelika Kalt
Susan Ivy Ochs Rainer Wieler |
| Résumé |
New U-Th/He data on apatites from the High Atlas of SW Morocco
provide for the first time constraints on the exhumation history of
the Atlas chain. U-Th/He ages on apatite range between 37 and 14 Ma
for the axial zone of the High Atlas, between 39 and 13 Ma in the
Sub-Atlas Zones and finally between 125 and 120 Ma in the
Anti-Atlas. Age-altitude relationships in the axial zone of the
High-Atlas suggest that exhumation attained 0.2 km/my for the
Middle Miocene whereas the Anti-Atlas belt to the south either 1)
did not undergo any protracted phase since the Late Jurassic-Early
Cretaceous, or 2) undergoes such phase very recently that cannot be
traced even with the lowest-temperature thermochronometer (U-Th/He
on apatite). Preliminary data from the Sub-Atlas zones on both
sides of the High-Atlas indicate that a 2-3 kms thick sedimentary
pile of post-Cretaceous age is missing. The timing of this erosion
is still unknown but will be constrained by thermal modeling
through future Apatite Fission-Track and additional U-Th/He data,
whereas sub-recent erosion rates are being determined by the
production of in situ cosmogenic analyses on present-day river
sands. |
| Mots-clés |
uplift, erosion, exhumation, neotectonics, north-africa, marocco, Denudation, Morocco, Anti- and High-Atlas, Tectonics, Fission-Track - and (U-Th)/He Thermochronometry, in situ cosmogenic exposure dating, North Africa, Anti-Atlas, High Atlas, fission track dating, (U-Th)/He thermochronometry, in-situ cosmogenic exposure dating |
| Type de projet | Recherche fondamentale |
| Domaine de recherche | Géologie |
| Source de financement | FNS - Encouragement de projets (Div. I-III) |
| Etat | Terminé |
| Début de projet | 1-10-2006 |
| Fin du projet | 30-9-2008 |
| Budget alloué | 262'455.56 |
| Contact | Angelika Kalt |