Schmalholz, Stefan and Schenker, Filippo (2016) Exhumation of the Dora Maira ultrahigh-pressure unit by buoyant uprise within a low-viscosity mantle oblique-slip shear zone. Terra Nova. pp. 1-8. ISSN 1365-3121
Full text not available from this repository.Abstract
The Brossasco-Isasca subunit (BIU) of the Dora Maira massif is currently the only known continental crustal ultrahighpressure (UHP) unit in the Western Alps. The peak pressure/ temperature conditions are 3.5–4.5 GPa/~730 °C; exhumation from ~3.5 GPa to ~1 GPa occurred within 2.2 +- 1.8 Ma, but the exhumation mechanism is incompletely understood. We present a conceptual model for the buoyancy-driven exhumation of the BIU inside a low-viscosity, dense mantle shear zone weakened by increased strain rates due to simultaneous strike-slip and subduction (oblique-slip) of the European plate. Two-dimensional thermo-mechanical models simulate such a buoyant uprise of an ellipse inside an inclined layer. Simulations (i) show the feasibility of the conceptual model, (ii) fit the pressure/temperature/time record and (iii) constrain effective viscosities. The model is compatible with the (i) small volume of continental crustal UHP rock in the Western Alps, (ii) minor erosion during exhumation and (iii) strike-slip deformation during the exhumation period.
| Item Type: | Scientific journal article, Newspaper article or Magazine article |
|---|---|
| Subjects: | Physical sciences > Geology > Earth science Physical sciences > Geology > Geophysics Physical sciences > Geology > Geology not elsewhere classified |
| Department/unit: | Dipartimento ambiente costruzioni e design > Istituto scienze della terra |
| Depositing User: | Filippo Schenker |
| Date Deposited: | 20 Sep 2016 11:30 |
| Last Modified: | 20 Sep 2016 11:30 |
| URI: | http://repository.supsi.ch/id/eprint/7726 |
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