Active Faulting in South Viotia Region, Central Greece: Segmentation, Stress Analysis and Extensional Strain Patterns

Athanassios Ganas¹, Vincenzo Spina², Nikolitsa Alexandropoulou¹, Athanassia Oikonomou¹, and George Drakatos^1
1National Observatory of Athens, Athens, Greece
²University of Camerino, Camerino, Italy

We studied two active structures of Pliocene-Quaternary age in Southwestern Viotia. This is a region of low finite strain, located between the Quaternary rifts of the Gulf of Corinth and the Gulf of Evia. The faults are segmented into several segments with an average strike of NE-SW. The architecture of the fault zones is characterized by a 10-20 cm thick gouge rock, observed along the fault plane on the footwall side. At several localities along strike we observed a well-defined basal strip of un-eroded fault plane that represents the width (uplift) of the last co-seismic slip. The width of the strip ranges 20-30 cm. Slip inversion data show a change in orientation of the mean orientation of sigma3 (least principal stress) from NW to NE which implies the existence of a structural boundary between the active faults of the Gulf of Corinth and the active faults inside the Evia graben.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece