Can there be island arcs on folded mountains?
Yes, island arcs can form on folded mountains. To understand why, let's first explain what folded mountains and island arcs are.
Folded mountains are formed by the compression of tectonic plates, where two continental plates collide or an oceanic plate collides with a continental plate. The immense forces created during these collisions result in upward, sideways, and downward folding of the Earth's crust, leading to the formation of mountain ranges with characteristic folds and uplifted peaks.
On the other hand, an island arc is a curved chain or group of islands that form in an oceanic area where tectonic plates converge and one oceanic plate is subducted beneath another. In this subduction zone, the descending plate gets pushed down into the Earth's mantle, forming a deep trench. As the subducted plate sinks deeper, it begins to melt, generating magma. This magma rises to the surface, forming a series of volcanic islands known as an island arc.
Now, back to the original question. Island arcs can indeed form on folded mountains, but it is not a common occurrence. In most cases, island arcs are associated with subduction zones in oceanic areas, where an oceanic plate sinks beneath another plate. However, under specific geologic conditions, if a continental plate with a folded mountain range collides with an oceanic plate, a subduction zone can develop between them. In these cases, a new island arc can form on the oceanic plate as it subducts beneath the folded mountain range.
So, while it is less common than the formation of island arcs in typical oceanic subduction zones, it is possible for island arcs to occur on folded mountains if the right tectonic conditions are present.