The Alps, Caucasus, and Mediterranean Mountain Belts

The mountain belts stretching across southern Europe and into the Caucasus are the product of the same broad tectonic story: the slow closure of the ancient Tethys Ocean as Africa, and the smaller Adriatic microplate riding ahead of it, converged with the Eurasian Plate through the Mesozoic and into the Cenozoic. The main Alpine orogeny intensified during the Oligocene and Miocene epochs, roughly 30 to 10 million years ago, thrusting up thick stacks of oceanic and continental sediment into the folded and faulted ranges seen today. This same collisional system extends, geologically, into the Carpathians, the Balkan ranges, and the Caucasus, together forming part of what geologists call the Alpide belt, a roughly 15,000-kilometer arc of young mountains running from the Atlas Mountains of North Africa, through the Pyrenees, Alps, and Carpathians, to the Caucasus, the Zagros of Iran, and onward to the Himalayas and the volcanic arcs of Indonesia. After the circum-Pacific Ring of Fire, the Alpide belt is the second most seismically active zone on Earth.