Strain rates of the syn-tectonic Symvolon pluton (Southern Rhodope Core Complex, Greece): an integrated approach combining quartz paleopiezometry, flow laws and PT pseudosections

Eugenio Fazio (1), Gaetano Ortolano (1), Roberto Visalli (1), Rosolino Cirrincione (1), Patrizia Fiannacca (1), Hartmut Kern (2), Kurt Mengel (3), Antonino Pezzino (1) & Rosalda Punturo (1)
(1) Department of Biological, Geological and Environmental Sciences, Catania University, Corso Italia 57, 95129 Catania, Italy. (2) Institute of Geosciences, Kiel University, Olshausenstrasse 40, 24098 Kiel, Germany. (3) Institut für Endlagerforschung, Clausthal University, Adolph-Roemer-Strasse 2A, 38678 Clausthal-Zellerfeld, Germany. Corresponding author e-mail: efazio@unict.it.

We studied the mylonitic granodiorites belonging to the Symvolon pluton from the Kavala Shear Zone (Rhodope Massif, NE Greece), to determine strain rates and refining the tectonic exhumation model of this area. With this purpose, we combined a quantitative microstructural analysis with an image assisted thermodynamic modelling. In particular, three samples exhibiting increasing stages of deformation were selected to estimate PT conditions of the mylonitic event by means of a quantitative mineral-chemical study realized via statistical data handling of X-ray maps. Obtained PT constraints were then used in conjunction with quartz paleopiezometry combined with flow laws, to estimate the amount of mean strain rate achieved during the shearing evolutionary stage of these rocks. Such multifaceted approach allows us to infer strain partitioning and pluton cooling rate during the mylonitic evolution, obtaining an average strain rate of 7.5 * 10^-12 (s^-1).

mylonites, quartz paleopiezometry, shear strain rate, GIS based X-Ray map classification, pseudosection.