Structural investigations along a low-angle normal fault zone (Kythnos, Greece)

Recent field investigations have revealed a high-strain zone in the south of Kythnos (Greece). Massive layers of ultrafine-grained Mn-rich calcitic mylonitic marbles and several generations of cataclasites hint at a high-strain event in the crust and are associated with a low-angle shear zone. We investigate fold-fault-relationships and deformation events preceding and post-dating normal faulting and compare the tectono-metamorphic history with adjacent islands in the Western Cyclades

Characteristics of low-angle normal fault formation on Kea (Western Cyclades, Greece)

The geology of Kea Island shows further evidence for low-angle normal fault (LANF) formation in the Western Cyclades. Structural investigations have demonstrated the existence of a hitherto unrecognised ductile-brittle shear zone with strikingly consistent top-to-SSW extensional kinematics together with a WNW-ESE oriented shortening component. The tectonostratigraphy comprises a >380 m thick, shallowly-dipping schist-calcite marble unit, overlain by ca. 150 m thick fault rocks consisting of cohesive cataclasites, ultramylonitic calcite marbles, brecciated dolostones and protomylonitic calcite marbles. The presence of blueschist-facies lenses and 40Ar/39Ar geochronology point to a significant role of LANFs in exhumation processes and greenschist-facies overprint during Miocene crustal evolution