The Greater Caucasus Mountains:

8/1 The Greater Caucasus Mountains: A Natural Laboratory for Understanding the Initiation of Continental Collision”. Presented by Nathan Niemi, Univ. of Michigan.

The Greater Caucasus Mountains lie at the southern margin of Eurasia, and accommodate nearly 50% of present-day convergence in the Arabia-Eurasia continental collision zone. Despite containing some of the highest peaks in Europe, geologically recent caldera-forming volcanic eruptions, and a historic record of large, destructive earthquakes, the tectonic evolution and seismic hazard of this region are poorly known relative to other continental collision zones. New geologic data suggests that the Greater Caucasus are remarkably young, perhaps less than ~6 million years old, and that the mountains accommodate most of the modern plate tectonic motion between the Arabian and Eurasian continents.  The Greater Caucasus also display a number of characteristics that may be unique in active continental collision zones on Earth today, including considerable spatial variations in deformation rates measured by GPS positions, and deep (>100 km) earthquakes.  These characteristics lead to the inference that the Greater Caucasus may be transitioning from oceanic subduction to continental collision, capturing a fleeting process in the life cycle of plate tectonics. Thus, the region may be a remarkable natural laboratory to decipher the tectonic processes associated with the initiation of continental collision.  Video