Reassessing the age of Karpathos ophiolite (Dodecanese, Greece): consequences for Aegean correlations and Neotethys evolution
Résumé
While the Neogene history of the Eastern Mediterranean region is now fairly well understood,
our knowledge of older regional palaeogeographies is less accurate, especially the positions of
blocks and nappes constituting the Aegean Islands prior to the Cenozoic. Our study focuses on
the ophiolite exposed on the island of Karpathos (Dodecanese), which is located in the Aegean
fore-arc at a pivotal position between the ‘western’ and ‘eastern’ ophiolites of the Mediterranean
region and where conflicting Late Jurassic and Late Cretaceous ages have led to diverging tectonic
and palaeogeographic interpretations. To test these ages, we targeted the radiolarian
cherts that depositionally overlie the ophiolite and extracted diagnostic radiolarian assemblages
ofAptian (∼125−113Ma), early–middle Albian (∼113−105Ma) and Turonian (∼93.9−89.8Ma)
ages. These results suggest that previous Late Cretaceous K–Ar isotopic ages (from 95.3 ± 4.2 Ma
to 81.2 ± 1.6 Ma) may have been reset by Late Cretaceous metamorphism or affected by argon
loss. Overall, the new Early Cretaceous ages show that the Karpathos ophiolite should not be
correlated with the Pindos Nappes of Greece or the ophiolites of Cyprus or Syria but rather with
the Lycian Nappes of Turkey and their root located in the Izmir–Ankara–Erzincan Suture Zone.
Therefore, the Karpathos ophiolite represents a remnant of the Northern Neotethys, not the
Pindos Ocean or the proto-Eastern Mediterranean Basin.
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