Rockall part of the deeply eroded Rockall Igneous Centre that was formed as part of the North Atlantic Igneous Province, approximately 55 million years ago, when the ancient continent of Laurasia was split apart by plate tectonics. Greenland and Europe separated and the northeast Atlantic Ocean was formed between them, eventually leaving Rockall as an isolated islet. The RV "Celtic Explorer" surveyed the Rockall Bank in 2003. The Irish Light Vessel "Granuaile" (the same name as the steamer on the RIA 1896 botany survey) was chartered by the Geological Survey of Ireland, on behalf of the Department of Communications, Marine and
Mariana Trough Iwo Jima), and Iwo Jima . Rifting and spreading are inferred to be propagating northward at a rate of 10 to 40 cm/year , so the variations in tectonic and magmatic style seen along-strike north of 18°N provide an example of the sequence of events that occur at any one section across the back-arc basin as the rift evolves from updoming through rifting to true spreading. Mariana Trough The Mariana Trough is an active back-arc basin in the western Pacific Ocean . It is an integral part of the Izu-Bonin-Mariana Arc system. The Mariana Trough stretches 1300 km from north