INSIGHTS INTO HYDROTHERMAL ACTIVITY IN THE ITI OPHIOLITE (CENTRAL GREECE)
Scarce intensely epidotised doleritic dykes, up to 1.5 m thick, penetrate in sharp contact serpentinised peridotites of the remnant ophiolite nappe of the Iti ophiolite. They are generally whitish rocks characterised by distinct and irregularly distributed, olive-green areas within the rock mass. Petrographic evidence reveals that their assemblage is dominated by quartz and epidote. Albite, chlorite and titanite occur as accessory phases. Minor opaque minerals are represented by magnetite, pyrite and chalcopyrite, as well as relic Cr spinel,. The mineral assemblage of the studied rocks comprises replacement products of the original phases under greenschist facies conditions. Moreover, the almostexclusive bi-mineralic (quartz + epidote) assemblage of the altered doleritic rocks, as well as obliteration of the original doleritic textures imply extensive recrystallisation, controlled by hydrothermal circulation. The compositions of the phases in these dykes mark the most alteration-resistant chemical components that have the potential to remain in their original associations, during such extensive recrystallisation.