Friday, April 26, 2013

METEORA – Halfway to Heaven

Possibly nowhere else on earth combines so rare a geological environment with a unique human settlement than the Meteora World Heritage site of Greece. The astounding rock pinnacles of Meteora rise ~500m above the Plain of Thessaly, an awe-inspiring view from afar. As early as the 9th century, hermitic monks climbed the rock spires, and began to live within erosional fissures in the formations. Between the 11th and 17th century, twenty-four monasteries were build atop the pinnacles, six remaining in use to this day.

The protection of the area as a sacred site has also provided centuries of environmental protection. Wandering among tens of rock spires, the sheltered areas below are micro-climates that harbor endangered species and endemic plant species that co-exist with traditional herding.

When we take friends and students to visit, we are always asked – how old are the spires of Meteora? This depends on what one interprets as their origin:
--The conglomerates that make up the pinnacles include cobbles that date to the oldest rocks found in Greece to date, 700 million years in age.
--The conglomerates themselves are Miocene in age, deposited about 21 million years ago.
--The terrain including the conglomerates was upraised, tilted about 12 degrees, and weathered to a level surface by about 700,000 years ago.
--Sometime since then, weathering of the conglomerates has preferentially eroded softer deposits and cracks, ultimately resulting in the formation of the spires. Probably the greatest erosion occurred with the aid of fluctuating weather conditions present during the ice ages, helped along by ice fracturing and interglacial rainy climates.
--Uplift and erosion continues to date, and the spires are still emerging from the landscape.

So, how old are the rock spires of Meteora? They are as old as the oldest rocks of Greece and as young as today.

Photo: Dina Ghikas

Refs: The Birth of Meteora, Rassios, Ghikas, Batsi @2013.

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