Karoly HIDAS, InSiDe-Strain



Research leading to these results was funded by the European Union Framework Programme 7 (EU-FP7/2007-2013) Marie Curie postdoctoral fellowship PIEF-GA-2012-327226 (InSiDe-Strain, 2013-2015)

Fluid-assisted strain localization in the mantle

In collaboration with

Carlos J. GARRIDO

Why to study mantle shear zones?

The deep interior of the Earth usually deforms ductilely and strain localization in the mantle play an essential role in plate tectonics.
Fluids and melts are known to have an impact on rheology: feedback between deformation and fluids in the mantle

Sampling

Fig. 1 - Outcrop of a ca. 2 km long peridotite shear zone, that progressively narrows from dozens of meters to less than a meter in the Ronda massif, southern Spain.

Fig. 2 - Photomicrograph of a shear zone thin section under cross polarized light.

Results

Fig. 3 - EBSD phase map of a thin section showing the redistribution of mineral phases inside the shear zone. Color coding indicates olivine (red), orthopyroxene (blue), clinopyroxene (green), spinel (gray) and amphibole (light blue).

In the shear zone:

redistribution of olivine and orthopyroxene at the cm-scale;
phase mixing of olivine and orthopyroxene in the finest-grained, orthopyroxene-rich domains;
abundance of amphibole in the orthopyroxene-rich domain.

Implications

heterogeneous phase redistribution in the shear zone is possibly achieved through fluids (dissolution-precipitation) in the course of strain localization;
dissolution-precipitation creepmay be an effective deformation mechanism to localize strain in the cold parts of the mantle wedge;
dissolution-precipitation creep may influence the deformation beyond the serpentinite stability in the incoming slab during its bending and faulting in the outer rise of subduction zones, thus may lead to weakening of the mantle deeper than the peridotite-to-serpeninite hydration reactions;
fluid-assisted strain localization may link high temperature ductile deformation to shallow serpentinite faults.

Publications and meeting abstracts

Hidas, K., Garrido, C.J., Tommasi, A., Padron-Navarta, J.A., Thielmann, M., Konc, Z., Marchesi, C., Frets, E. (2014) Ductile strain localization in the shallow subcontinental lithospheric mantle during the final exhumation of the Ronda massif (Betic Cordillera, S-Spain). 6th Orogenic Lherzolite Conference, 4-15 May, Marrakesh, Morocco, Abstract Volume

Hidas, K., Garrido, C.J., Tommasi, A., Padron-Navarta, J.A., Thielmann, M., Mainprice, D., Barou, F., Konc, Z., Marchesi, C., Frets, E. (2014) Examples for fluid-assisted ductile strain localization in the shallow subcontinental lithospheric mantle during the final exhumation of the Ronda massif (Betic Cordillera, S-Spain). Gordon Research Conference on Rock Deformation, 17-22 August, Andover (NH, USA)

Hidas, K., Tommasi, A., Garrido, C., Padron-Navarta, J.A., Marchesi, C. (2014) Strain localization in the subcontinental lithospheric mantle during the final exhumation of the Ronda Peridotite (Betic Cordillera, S-Spain). European Geosciences Union General Assembly 2013, 27 April-2 May, 2014, Vienna, Austria, Geophysical Research Abstracts 16, EGU2014-12425.

Hidas, K., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Mainprice, D., Barou, F., Marchesi, C. (2014) Fluid-assisted ductile strain localization at low temperature in the shallow subcontinental lithospheric mantle (Ronda massif, Betic Cordillera, S-Spain). Gordon Research Seminar on Rock Deformation, 16-17 August, Andover (NH, USA)

Hidas, K., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Mainprice, D., Barou, F., Marchesi, C. (2014) Fluid-assisted ductile strain localization in the shallow subcontinental lithospheric mantle (Ronda massif, Betic Cordillera, S-Spain). AGU Fall Meeting 2014, 15-19 December, 2014, San Francisco, CA, USA

Hidas, K., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Mainprice, D., Vauchez, A., Barou, F., Marchesi, C. (2015) Ductile strain localization assisted by fluids in the shallow subcontinental lithospheric mantle (Ronda massif, Betic Cordillera, South Spain). Micro-Dynamics of Ice (Micro-DICE) ESF Research Networking Programme 2015, 30 March-1 April, 2015, Montpellier, France, Abstract Volume

Hidas, K., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Mainprice, D., Vauchez, A., Barou, F., Marchesi, C. (2015) Fluid-assisted strain localization in peridotites during emplacement of the shallow subcontinental lithospheric mantle. European Geosciences Union General Assembly 2015, 12-17 April, 2015, Vienna, Austria, Geophysical Research Abstracts 16, EGU2015-15729

Hidas, K., Garrido, C.J., Tommasi, A., Padron-Navarta, J.A., Mainprice, D., Vauchez, A., Marchesi, C., Barou, F. (2016) Feedback of fluids on ductile strain localization in the upper mantle. European Geosciences Union General Assembly 2016, 17-22 April, 2016, Vienna, Austria, Geophysical Research Abstracts 18, EGU2016-7048.

Hidas, K., Garrido, C.J., Tommasi, A., Padron-Navarta, J.A., Mainprice, D., Vauchez, A., Marchesi, C., Barou, F. (2016) Feedback of reactions on ductile strain localization in the shallow subcontinental lithospheric mantle. 88th Congress of the Italian Geological Society, 7-9 September, 2016, Naples, Italy, Abstract Volume.

Hidas, K., Tommasi, A., Garrido, C.J., Padron-Navarta, J.A., Mainprice, D., Vauchez, A., Barou, F., Marchesi, C. (2016) Fluid-assisted strain localization in the shallow subcontinental lithospheric mantle. Lithos 262, 636-650