Converging Plate Boundaries http://library.thinkquest.org/17457/platetectonics/4.php Plates are created and grow at diverging plate boundaries. Plates come together and are destroyed at converging plate boundaries. The great pressures exerted when plates collide create spectacular features. Converging plate boundaries are divided into two categories: Subduction zones Collision zones Subduction zones develop where oceanic plates collide with continental plates. The oceanic plate is comprised of heavier basaltic rock and descends below the continental plate. The oceanic plate descends into the asthenosphere and the materials of the oceanic plate recycle back into the asthenosphere. The ocean plate was originally created at a mid-ocean ridge millions of years before is now recycled back. This process ranges from 150 to 200 million years. Tectonic Processes at Subduction Zones Visit the following website http://library.thinkquest.org/17457/platetectonics/4.php 1. Describe how each of the following features are formed due to subduction: a. Earthquakes b. Oceanic trench c. Volcano Volcanism Volcanic activity at subduction zones are often violent! 1. Read page 106 in your textbook and explain why they are so violent. 2. What are volcanic arcs? Provide four examples of volcanic arcs.