Editing Oceanian realm (section)

==Geology==
Oceania is geologically the youngest realm. While other realms include old continental land masses or fragments of continents, Oceania is composed mostly of volcanic [[high islands]] and [[coral atoll]]s that arose from the sea in geologically recent times, many of them in the [[Pleistocene]]. They were created either by [[Hotspot (geology)|hotspot]] volcanism, or as [[island arc]]s pushed upward by the collision and [[subduction]] of [[tectonic plate]]s. The islands range from tiny islets, [[sea stacks]] and coral [[atoll]]s to large mountainous islands, like [[Hawaii]] and [[Fiji]].