The Skouriotissa (SK) massive sulfide deposit (VMS) formed on top of the extrusive sequence of a fossil spreading ridge at Cyprus. At SK mine, we have sampled outcropping metabasalts along a 200 m-long cross section ranging from the fossil seaflloor to the VMS envelop.

- Quartz-chlorite rocks of metasomatic origin outcrop at the seafloor. They formed from deep hot fluids which reacted in situ with extrusive basalts and mixed with seawater. The NIR spectrum of SK Fe-Mg clinochlore has a higher reflectance than that of FRT000033C Nili Fossae chlorite (Carter et al., 2013); 0.35- 0.7 compare to 0.12-0.25, respectively). By its overall reflectance and spectral properties in the 2-2.6 µm range, the Martian chlorite is closer to the Al-poor Fe-Mg-Ti prochlorite SMR14 (Clark et al., 2007).

- Pyrite-bearing quartz-smectite and corrensite (ordered S/C mixed layer) rocks characterize the VMS envelop. They are deeply leached and metasomatic.

-Saponite zeolite metabasalts are found inbetween the fossil seafloor and the VMS. Bulk rock analyses and advanced DRX studies allow discrimination of two groups among these metabasalts. A former group, still showing primary basaltic minerals, is less argilllized and less affected by medium temperature zeolitization (analcime stage). It shows limited growth of a C/Sm saponite with dominant chlorite over Ca-rich smectite. Group 2 saponite metabasalts have undergone both advanced argillization and long lived zeolitization from medium to low temperature (analcime-philipsite association). Group 2 saponite contains Sm/c mixed layer with Mg-rich smectite and subordinate chlorite. The IR spectrum of a Group 1 metabasalt, interpreted in terms of 80% Mg-chlorite-20% Ca-Fe smectite, is similar to that of Tyrrhena Terra CRISM 1 phyllo (Loizeau et al., 2012).

- SK basalts are presently altered to illlite-smectite-bearing rocks due to the flow of acidic drainage waters (17°