Journal of the Virtual Explorer

Based on published geochronological data and on current structural observations, we suggest that Serifos represents a further example of a metamorphic core complex for the Aegean region (Lister et al., 1984) that was exhumed during the Miocene. An earlier SSW-directed mid-crustal shear zone mylonitized some or all of an older granitic body together with its amphibolite / orthogneiss / marble host rocks. Based on the syntectonic relationship of high-temperature skarns and on preliminary ion microprobe U-Pb zircon spot age dating, we speculate that the older granitic body intruded syntectonically in the Late Eocene. At a late stage of S-directed shearing, the mylonitized granite has been altered by high-temperature skarns. In the Late Miocene, this shear zone (exhumed by ongoing extension in the intervening period to higher crustal levels) was, in turn, intruded and cross-cut by the main Serifos granodiorite pluton and its associated dacitic dykes. Although these granodiorite intrusions cut the pre-existing metamorphic fabric formed at structurally deeper levels, they are themselves deformed by a network of S-directed brittle / ductile low-angle shear zones at structurally higher levels, the result of ongoing N-S extension. This N-S extension is further documented by additional intrusions of numerous dykes that mainly cross-cut the detachment and follow a conjugate high-angle WNW-ESE striking normal fault system.