21. Volcanic rocks produced in these island arcs are found among the ophiolites of the Penninic nappes. 22. These are zones of variably island arc terranes. 23. Generally, orogenic belts consist of long parallel strips of crust, produce volcanoes, and build island arcs . 24. The subduction zone forming the South Sandwich Trench lies to the east of the island arc . 25. Trenches are generally parallel to a volcanic island arc , and about 200 km from a volcanic arc. 26. This volcanic active island arc has submerged ancestors in Jane and Discovery banks in the southern ridge. 27. A second theory involved collision of the continent with an island arc above a west-dipping subduction zone. 28. Oceanic trenches are a distinctive morphological feature of volcanic island arc , and about from a volcanic arc. 29. The islands are all active volcanoes lying atop an island arc that stretches south to the Marianas. 30. The island arc is formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate.
