A controversial theory proposed in 2010 and put forth in Science Daily explains that Mt. Etna came from intraplate volcanism and induced decompression melting of the upper mantle when movement of the African plate caused magma to flow towards the island of Sicily. Most volcanoes form near plate boundaries when the Earth is tectonically active. Mt. Etna and its nearby volcanoes formed far away from associated active boundaries.
Geophysicist Dr. Wouter Schellart studied the chemistry of volcanic rocks of the area surrounding Mt. Etna and noted these mountains are off to the side and away from the Calabrian subduction zone plate boundary. This is the closest tectonic plate action to the volcano, yet it is too far away to explain the existence of Mt. Etna.
Schellart came up with a relatively new theory that the Earth's mantle, the layer below the crust, moved upwards near the island of Sicily. Mt. Etna is near the boundary of the Eurasian and African plates, but the volcano formed from magma that arrived from different sources.
Mt. Etna is a stratovolcano that first formed around 500,000 years ago; the mountain began to rise 35,000 years ago. The volcano has erupted around 200 times since 1500 B.C. The most recent eruption began in 2007, according to Geology.com. Mt. Etna is the largest active volcano in Italy.