The Geology of Crete
Geological surveys have shown that Crete, like the rest of Greece and the neighboring Turkey, lay for millions of years at the bottom of a vast sea that geologists call Tethys.
Around 30 million years ago, the Tethys seabed began to rise and a vast land mass, named Aegeis by geologists, gradually emerged where present-day Greece, Turkey and the Aegean Sea are today. What is now Crete was formed on its southern edge.
Huge geological upheavals, subsidences and uplifts were to follow before the Aegean and Crete took on the forms we know today, with the latter emerging out of three or four smaller islands. What we do know for certain is that for the last 2 to 3 million years at least, there was no land bridge between Crete and neighboring island masses. This geographical isolation led to the evolution of local species of flora and fauna which were endemic to the island.
Rock formations on Crete today mainly consist of:
• Crystalline schist, with clusters of granite, granitic gneiss and phyllite (a metamorphic rock). Such rock formations are chiefly to be met with in western Crete, west of the White Mountains, and only sporadically in other parts of the island.
• The Olonos-Pindus zone: An extension of the zone that extends down the length of the Pindus range and into the central Peloponnese, consisting of limestone, dolomite, flysch and schist, which form the majority of rock types on Crete.
• Neogenic rock strata: Formed from the erosion of older strata, these are chiefly found in central Crete, with some scattered examples in the rest of the island.
• Igneous rocks: Peridolites and diabase (a kind of basalt) only exist south of Rethymnon.